I baked the best butter cake today, and this is the 1000th cake I baked.
No. I have baked more cakes than that. Throughout the years, I made a variety of cakes and desserts, but butter cake is on top of my list.
By now, you should have guessed that I work in a bakery!
The best butter cake without frosting is the most sellable cake in my cafe. The formula of this cake has survived a gallant of tests in response to the request from our customers. The current recipe is rich in butter, has less sugar and does not include any artificial flavoring agents.
Time tested best butter cake indulges by my loyal customers
I finally decide to reveal the recipe, not because I was reluctant to share, but is due to the formula was ever-evolving. The present version is the most successful one, with great flavor and smooth texture. If you are looking for a great recipe with an extensive list of notes that explain every step, this will be one recipe post that you should read on. (Self-bragging 🙂 )
Before you read further, I want to make it clear that I am NOT a pastry chef. I never attended baking school, and write this butter cake guide from the perspective of a pharmacist turned restaurateur. I am a cooking nerd that drills into every aspect of food at the meticulous level like writing a Ph.D. thesis. My experience as a pharmacist has a huge influence on my approach to baking. I treat my kitchen as a laboratory. Sugar, flour, butter, and eggs are part of the ingredients of formulating a chemical concoction.
After years of souls searching, desk work, experiments, failure, excitement, frustration, setback and calamity in the kitchen, the search finally come to the finale. I think I have found the holy grail of the best butter cake formula.
This guide includes all the knowledge, mistakes, and experiments I carried out in the kitchen, and working under a less than ideal situation. I think many practical aspects of baking are not taught in a well-equipped kitchen in culinary school, as the thing might turn against you in reality. I hope this guide will provide the answer to your questions about baking and get the insight of how to bake the perfect butter cake.
Once you have mastered the basic techniques, you can improvise the recipe with other ingredients and flavor agents complete with attractive decoration.
Let’s dive in to look at the details.
Section one- The choice of ingredients for butter cake
There are only a few fundamental ingredients that determine the texture and flavor of the cake. Let’s take a look at how do I choose these items for my butter cake.
My regular baking ingredients supplier told me that the flour I use is wheat flour which contains eight percent protein.
The protein in the flour plays a significant role in making cakes. When flour and water mix, the gluten proteins in the flour will bond to each other and form an elastic mass that can expand to accommodate gas bubbles produced. 
Gluten is the tough and stretchable protein that forms when the flour mix with water. It contributes to the structure of the cake. However, too much protein in the flour can cause the cake become rubbery.  I find that the wheat flour with 8% of gluten give just adequate structural support and yet does not toughen the cake. In general, wheat flour with 8 to 10 percent protein is ideal for making butter cake.
"Use wheat flour with eight to ten percent of protein content for butter cake."
I use medium size fresh egg which is about 55g per egg. The size of the egg does not affect the quality of my cake.
However, I always prefer to measure the eggs by weight instead of the number of eggs required. The size eggs sold here ranges from 48g to 60g per piece. Since the largest one is 25% bigger than the smallest one, it is only logical to measure by weight to get the correct quantity.
A batch of my butter cake requires 1200g of the egg. I crack all the eggs without worrying about the size of the eggs until it reaches the required quantity shown on the weighing scale.
Since my egg vendor supplies eggs to me twice a week, I always can get the freshest egg available. I store the eggs at room temperature since I can use up all of them within three days. If you are making it at home, please store the eggs in the refrigerator.
Use fresh eggs to make the best butter cake as there are only a few ingredients to contribute flavor. You can find out the freshness of the eggs by putting them in a bowl of water. If the eggs sink to the bottom, the eggs are fresh. Bad eggs will float on the surface of the water.
"Always choose the freshest eggs to make the cake."
Milk and fruit juice
Milk and fruit juice provide additional moisture to the cake. I use full cream milk which contains 3.3% of milk fat for the basic butter cake formula. You can use low-fat milk, but it will not give you the best butter cake flavor you want.
I am looking for the best flavor, not the best food for health. So just forget about the low-fat diet and indulge in what is nice to eat.
You can substitute milk with fruit juice If you make a fruit cake. My orange cake contains orange juice instead of milk.
"Add full cream milk or fruit juice to the formula for additional moisture."
I keep the amount of baking powder to the minimum since the creaming of butter and sugar will provide sufficient leavening power. The amount of baking powder I use is only 6g for 1200g of flour.
Most of the baking powder sold over the counter are double acting. This type of baking powder releases the gas in two phases. Carbon dioxide will form once the baking powder contact with water from the egg or milk. This process takes place immediately, and gas will release within two minutes due to an immediate chemical reaction.  The second phase happens during baking when the temperature rises to about 60°C. At this time, another chemical reaction will trigger by the heat in the oven. The expansion of gas within the cake batter will cause the cake to rise.
On the contrary, the single acting baking powder does not have the chemical to form more gas during the second phase in the oven. Since all the gas will release right after the baking powder contact with water, you need to work immediately as the leavening effect will diminish over time.
Therefore, double acting baking powder is more reliable and is always my choice.
"Use double acting baking powder, and make sure it is not expired."
Salt balances the sweetness of sugar and give a more alluring flavor combinations to the cake. I alway use unsalted butter for making cakes, as I can control the amount of salt in the recipe. My magic formula is one gram of salt for one hundred gram of flour. This amount of salt balances the sweetness of sugar perfectly.
Some brands of butter are salted, mainly as table butter for the bread. Most of the salted butter contain one percent of salt, and therefore you should omit adding salt in such cases.
"Use one percent of salt for the best result."
I use either granulated or castor sugar to make butter cake. The granulated sugar I get in Malaysian is slightly courser than the castor sugar. Both types of sugar produce an excellent result as long as I cream the sugar with butter until very light and fluffy.
I have not tried coarse sugar (those sugar to make syrup) or icing sugar (for my melt-in-the-mouth cookies) in the butter cake formula. I am satisfied with the result of granulated or castor sugar, so I just stick to them.
"Use granulated or castor sugar."
The quantity and quality of the butter will affect the flavor of the cake.
As the name implies, the best butter cake should have rich butter flavor. I use 1300g of unsalted butter for every 1200g of flour for one batch of cake. (Read on to see how I set up my butter cake formula.). The high amount of butter in this recipe satisfied the most uncompromising palate of my customers.
I have used different brands of unsalted butter for my cake in the last few years. Each of them results in a slightly different flavor and color.
I am not endorsing a brand, but SCS brand of butter has the best flavor among all the butter I used. The result showed that expensive brands provide a better flavor, although this might not happen in all cases.
I only use one trusted brand of butter because it gives me the best flavor. It also assures the consistency of the quality which is of paramount importance in any cafe and bakery.
"Use the best butter available. Butter is the single most important ingredient for you cake."
Section two- How do I set up the butter cake recipe
I follow some rules throughout my baking career. You can read about the set of rules here, but I am describing how I use it and break some of them along the way.
Before I discuss the details, here is the list of ingredients and their relative amount to flour. Note that I have rounded the quantity of flour to 100. When I mention 80 percent, that means I use 80g of a particular ingredient for every 100g of flour I used.
The relative quantity of ingredients for butter cake
Cake flour: 100g
Baking powder: 0.5g
Let me explain the rationale how I calculate the amount of each ingredient.
In reality, I used 1200g of flour to make four-eight inches square cake per batch. The quantity is 12 times of the above amount. You may notice that the amount of flour, egg, butter and sugar are quite close to each other. The formula of the basic pound cake consists of an equal amount of flour, egg, butter, and sugar. I improvised the pound cake formula to achieve the flavor the texture I want.
One gram of salt is the ideal amount for every 100g of flour. Salt balances the sweetness of sugar and makes the flavor more rounded. Bear in mind that the amount should be minimum and should only be a subtle presence.
I use far less than the accepted maximum amount which is four percent. The higher amount of baking powder can produce too much gas, forming larger bubbles and a coarser texture. the best butter should have a fine texture, smooth and soft likea sponge.
I only use 0.5% of baking powder to get a velvety and smooth texture. The creaming of sugar and butter will provide sufficient leavening effect to the cake.
The amount of egg is the same as flour in the recipe. Eggs give support to the body and structure of the cake. My goal is to formulate a butter cake which is soft and moist. In theory, more eggs mean more moisture since about 70% of the content of the egg is water. In fact, too much egg can make the cake dry, as a result of the denaturation of the protein. (Imagine eating hard boiled eggs). Therefore part of the moisture of the cake should come from the milk.
Years ago I read an article written by a veteran in baking. The article mentioned that the maximum amount of liquid content (egg + milk + juice) in a butter cake is twenty percent higher than flour. The amount of liquid in my formula is eighteen percent higher. I did try twenty percent, but the cake turned out to be unstable.
I only use full cream milk for my cake. There is 3.3% of milk fat in full cream milk, which contribute the best butter cake flavor and the soft texture.
The initial formula of my butter cake has 70g of butter for every 100g of flour. Over the years, I have amended the formula based on the feedback of my customers. Currently, I use 110g of butter for every 100g of flour to get a richer butter flavor. The cake with the higher amount of butter is more tender and softer. So far I have not tested anything more than 110g, as my customers are happy with it. However, I have seen other people make the best butter cake with a higher amount of butter. Celia of Foodelicacy.com uses 455g of butter and 310g of flour in her Nyonya butter cake, which means there is a whopping 146g of butter for every 100g of flour used. 
Sugar and butter are the tenderizers of the cake. Most professional bakers agree that the amount of sugar should be at least eighty percent of flour. I use a smaller amount of sugar now because my customers preferred cakes with lower sugar content.
The less amount of sugar is balanced by the higher amount of butter in the formula. As a result, the cake is still moist and tender.
Baking is more of science than art. I set up the formula based on the guideline that has been set by the professional and validated with recipe testing.
As you know by now, you do not need a recipe if you know the rationale. Formulate the recipe according to your wish.
In the following post, I will discuss how I bake the best butter cake and explain every step in detail. I hope it will be useful to you.
So stay tuned and I will post the “Part 2” of my best butter cake next week.
6. On food and cooking, The science and lore of the kitchen by Herold McGee