Vanilla Sponge Cake

I developed this sponge cake recipe after first making it for the coconut cake that I made for my dad's 90th birthday. It is more of a white sponge cake than a yellow, but it's most definitely vanilla in flavor. The texture is just right - soft, moist and fluffy, so I now use it as my go-to recipe for any dessert that requires a sponge cake. 

Ingredients:
1 tbsp. butter, room temperature (for the pans)
1 cup whole milk, room temperature
5 large egg whites, room temperature
1 large egg, room temperature
2 tsp. vanilla bean paste or vanilla extract
2 1/4 cups cake flour
1 1/2 cups sugar
1 tbsp. plus 1 tsp. baking powder
1 tsp. iodized salt
12 tbsp. (1 1/2 sticks) unsalted butter, cut into 12 pcs. (slightly cold)

1. Preheat oven to 350F.

2. Butter and flour two 9 x 2" round cake pans; line the bottoms with rounds of parchment (you can buy parchment rounds in some specialty food stores, or just use scissors and cut them out.

3. In a medium bowl, whisk together the milk, egg whites, whole egg, and vanilla bean paste or extract; set aside.

4. In the bowl of a stand mixer (use the paddle attachment), add the flour, sugar, baking powder and salt. 

5. With mixer on low speed, add the butter, one piece at a time.

 6. Continue beating until mixture resembles moist crumbs. 

7. Add all but 1/2 cup of the reserved milk & egg mixture and beat on medium until pale and fluffy, about 1 1/2 minutes. 

8. With mixer on low, add remaining 1/2 cup of milk & egg mixture. Increase speed to medium and beat 30 seconds more. Scrape down sides of bowl and mix for another 20 seconds. 

9. Divide batter evenly between the 2 cake pans and smooth tops over with a rubber spatula. 

10. Bake 22-25 minutes, or until toothpick inserted in the middle comes out clean. Let cool in pans on baking rack for 10 minutes. Run a small knife around the sides of the pan and invert the cakes onto a baking rack. Let cool completely, about 45 minutes.

Use in whatever cake recipe you'd like.