Single Layer Funfetti Cake

8 Reasons to Love This Recipe

1. It's easy to make.
2. Yields only one 6-inch single layer funfetti cake—but thick enough to be sliced into two layers!
3. Perfect for up to 6 people.
4. It's moist and tender—thanks to the added buttermilk!
5. Adding rainbow jimmies (or sprinkles) to your desserts is fun and makes people smile!
6. It's paired with a vanilla buttercream that is NOT made with powdered sugar.
7. It's wonderful for small dinner parties or birthdays, an intimate dinner, or a really nice way to treat yourself!
8. You can make your very own rainbow sprinkle mix for decoration!

Ingredients Needed

To make this moist and tender vanilla funfetti cake, you'll need the following ingredients:

• Cake Flour
• Baking Powder
• Salt
• Unsalted Butter
• Granulated Sugar
• 1 Egg
• Vanilla Extract
• Buttermilk
• Rainbow Jimmies (or sprinkles) + plus more for decoration (see below)

Substitutions

Cake flour substitute. If you do not have or have difficulty finding cake flour in your area, you can use the substitute shown below.

Whole Milk. You can use whole milk if you do not have buttermilk on hand. However, you can also use whole milk with two teaspoons of lemon juice for a closer thickness to buttermilk. Add the lemon juice into the ⅓ measuring cup first, then fill the remaining cup with the whole milk. Pour it into a small glass bowl and let it thicken for about 5 minutes.

I did not test this recipe using alternative flour, egg substitutes, dairy-free alternatives, or cake pans.

Homemade Cake Flour Substitute

Fear not if you don't keep cake flour on hand—you can make it at home! You only need all-purpose flour, cornstarch, and a sifter!

To make homemade cake flour:

1. Add one tablespoon of cornstarch to a ½ cup measuring cup.
2. Fill the remaining measuring cup with all-purpose flour.
3. Run the mixture through a sifter. Once is good, but twice is even better!

If you want to have a little more on hand, I recommend doubling the above recipe. Keep it stored in an airtight container either at room temperature or, in my preference, the freezer.

What is Flour Buttercream?

Flour buttercream, also known as Ermine buttercream or boiled milk frosting, is frosting made without powdered sugar.

Its ingredients include all-purpose flour, granulated sugar, salt, milk, vanilla extract, and unsalted butter.

While the process is slightly more time-consuming, the result gives you a less sweetened buttercream that is similar to a swiss meringue, with the creaminess of the classic American buttercream frosting.

How to Make Small Batch Vanilla Flour Buttercream

This buttercream is made in two parts and will take some time.

If you prefer to make my small batch of vanilla buttercream with powdered sugar, visit my Small Batch Vanilla Cupcakes recipe.

STEP ONE. Mix your all-purpose flour, granulated sugar, and salt together with a whisk. Add in the milk and whisk once more.

STEP TWO. Over low-medium heat, bring the mixture to a near boil, continually stirring with a spatula. It's also a good idea to scrape the bottom of the saucepan too. Your mixture will begin to thicken to the consistency of paste and have a wet, glossy look.

STEP THREE. Turn off the heat and continue to stir and scrape for 1-2 minutes more. This will help release some of the heat and remove some of the shine.

STEP FOUR. Pour the mixture evenly onto a plate (preferably one with a lip or an edge) and immediately cover it with plastic wrap, pressing it directly onto the mixture. This will keep the mixture from forming a skin. Let it cool to room temperature before continuing to the next step.

STEP FIVE. Before starting, ensure the butter is at room temperature and cut into cubes. Beat the butter using a stand or hand mixer for 2-3 minutes or until it's light in color and fluffy in texture.

STEP SIX. Add it one spoonful at a time and not all at once. Let each spoonful mix into the frosting before adding the next spoonful. Once it's all been added, scrape down the sides of the bowl, add in the vanilla extract, and mix on medium-high speed.

You can make either the thickened flour mixture or the flour buttercream 3-5 days in advance. Keep it stored in the refrigerator, then bring it to room temperature when ready to use.

For the vanilla flour buttercream, you should whisk it again with the mixer to bring it back to life.

Make Your Own Sprinkle Mix

If you want to mix things up a bit with the sprinkles you add to your 6 inch funfetti cake, here's a combination to try! Of course, the sky is the limit for the type of sprinkles you use as well as how many different combinations. For this mix, I used the following 3:

• Rainbow Jimmies (or Rainbow Sprinkles)
• Rainbow Nonpareils
• Rainbow Confetti Sprinkles

Note that the kind I used has natural coloring and is not super bold and bright. They're more muted in color.

Add a small amount to a jar with a lid (a ball canning jar will work well), make sure the lid is on good and tight, then shake it up. Wah-la—your own sprinkle mix!

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