Step 1

Measure out ingredients for the cupcakes: At least 30 minutes before mixing, take the butter (226 grams, 2 sticks), eggs (about 5 large), milk (170 grams, ¾ cup), and sour cream (180 grams, ¾ cup) out of the refrigerator to come to room temperature. Separate the eggs (you need 160 grams, ⅔ cup, of egg whites). Measure out the rest of the ingredients.

Step 2

Measure out ingredients for the buttercream: Take the butter (454 grams, 2 cups) out of the refrigerator to come to room temperature. Measure out the rest of the ingredients.

Step 3

Position the oven rack to the center position. Preheat the oven to 350°F/175°C. Prepare 2- 12 cup muffin tins with paper liners.

Step 4

Sift together the cake flour (345 grams, 3 cups), baking powder (2 teaspoons), and baking soda (½ teaspoon). Add the salt (½ teaspoon), whisk together, and set aside.

Step 5

In the bowl of a stand mixer fitted with the paddle attachment, or in a large bowl with a hand mixer, combine the butter and sugar (400 grams, 2 cups). Cream together on medium speed until very light and fluffy, about 5 minutes. Stop the mixer and scrape down the sides and bottom of the bowl halfway through mixing. The mixture should be very pale yellow after mixing.

Step 6

With the mixer running on medium/low speed add the vanilla extract (2 teaspoons) and almond extract (1 teaspoon). Next, slowly add in the egg whites while the mixer continues running. Scrape down the sides of the bowl periodically as you slowly incorporate the egg whites.

Step 7

Mix the milk and sour cream together. Alternate adding the dry ingredients into the bowl in three additions with the milk/sour cream mixture in two additions, starting and stopping with the dry ingredients. Mix on medium speed in between each addition until fully incorporated.

Step 8

Transfer the batter into the prepared muffin tins. Bake for about 18-25 minutes. Pull out of the oven when the cake is firm but springs back when gently pressed in on the center, or when a cake tester comes out clean.

Step 9

Cool the cupcakes in their pan for a few minutes before moving them to a cooling rack. Cool completely before frosting.

Step 10

In the bowl of a stand mixer fitted with a paddle attachment, or in a large mixing bowl with a hand mixer, beat the butter on medium speed for about 1 minute, until fluffy. Scrape down the sides and bottom of the bowl.

Step 11

Add the powdered sugar (600 grams, 5 cups) into the mixing bowl and start mixing on low until the sugar starts to combine with the butter. Turn the mixing speed up to medium-high and beat for about 3 minutes until the mixture is light and fluffy. Mix in the vanilla extract (2 teaspoons) and salt (½ teaspoon).

Step 12

Add a bit of milk or heavy cream (56-84 grams, 4-6 tablespoons) if needed to thin out the texture. If the texture becomes too thin, you can add a bit more powdered sugar until you get a spreadable consistency.

Step 13

Frost the cupcakes and top with sprinkles if using.