Vanilla Buttermilk Cake with Buttermilk Frosting

Happy Halloween (soon)! This cake is very delicious and has a soft, dense texture. 10/10, of course! Original recipe calls for "whole" buttermilk; I used the only kind I've ever found here, which is lowfat, and it worked perfectly :) 

**Note: I used purchased black decorating frosting for the design on top.**

Original recipe credit: https://swansdown.com/recipes/vanilla-buttermilk-cake/

Recipe below contains my modifications.

Ingredients:

for the cake--

1 c. (2 sticks) unsalted butter, softened

2 c. sugar

6 large eggs, separated

3 c. (356 g) Swans Down cake flour

1 T. baking powder

3/4 tsp. kosher salt

1 c. buttermilk

4 T. vanilla extract

for the frosting--

1 c. (2 sticks) unsalted butter, softened

1/4 c. butter flavored Crisco

2 1/4 lb. powdered sugar (it says 'sifted' on the original recipe; I forgot and it still turned out fine)

2/3 c. buttermilk

1 1/4 tsp. vanilla extract

1/4 tsp. kosher salt

Directions:

1. Grease and flour 2 (9") round cake pans, then line bottom of each pan with a circle of parchment, also greased and floured (on side face up only). Heat oven to 350°F.

2. In the bowl of a stand mixer, beat together butter and sugar on medium speed until fluffy (takes about 3-4 min).

3. Add egg yolks, one at a time, beating well after each.

4. In a separate bowl, whisk together the cake flour, baking powder, and kosher salt.

5. With mixer on low, gradually add flour mixture alternatively with buttermilk, beginning and ending with the flour mixture. Beat until just combined after each addition.

6. Beat in the vanilla.

7. In a separate (clean) bowl (with clean beaters), beat egg whites at high speed until stiff peaks have just formed.

8. Gently fold beaten egg whites, one-fourth at a time, into the cake batter.

9. Divide the batter as evenly as between the two prepared pans, spreading as best you can for an even top on each. Transfer to the oven and bake for 30 min, or until wooden toothpick inserted in center comes out clean (I had to go 5 min extra). 

10. Transfer pans to wire racks and let cakes cool in pan for 10 min, then turn out onto rack to finish cooling completely.

11. For the frosting-- In the bowl of a stand mixer, beat butter and shortening together on medium speed until creamy. 

12. Beat in the buttermilk and powdered sugar gradually, alternating between the two, then beat in the vanilla and kosher salt. Frost cake, serve, and enjoy!

(the black spots are, of course, from slicing through the black frosting)