One bowl Chocolate Cake and swiss meringue buttercream
 
 
Ingredients
For the chocolate cake:
  • 1¾ cups (220 g) all-purpose flour
  • 2 cups (400 g) granulated sugar
  • ¾ cup (90 g) Cocoa Powder
  • 2 tsp baking soda
  • 1 tsp baking powder
  • 1 tsp salt
  • 2 eggs, at room temperature, lightly beaten
  • 1 cup strong, hot black coffee or espresso
  • 1 cup buttermilk, room temperature
  • ½ cup vegetable oil
  • 1 tablespoon pure vanilla extract
For the swiss meringue buttercream
  • 5 large egg whites (150 grams)
  • 1¼ cups (200 gms or 250 grams if you want it sweeter) granulated sugar
  • 1 pound (4 sticks) unsalted butter, softened, cut into cubes
  • 2 tsp pure vanilla extract
  • pinch of salt
Instructions
  1. Preheat oven to 350 F.
  2. Prepare 2 x 9" (or 3 x 8" for slightly shorter layers) cake pans with butter and flour or parchment paper.
  3. In bowl of electric mixer fitted with the paddle attachment, sift all dry ingredients. Add remaining ingredients to mixture and mix for 2 minutes on medium speed. Start slow, so that you do not splash everything, and then increase the speed to medium.
  4. Divide the liquidy batter among prepared pans.
  5. Bake for 20 minutes and rotate pans in oven. Bake another 15 minutes, or until tester comes out clean. Do not over bake.
  6. Cool on wire racks for 20 minutes then gently invert onto racks until completely cool.
For the swiss meringue buttercream:
  1. Place egg whites and sugar in a heat proof bowl and place over a pot of simmering water. Heat whites while whisking continuously until they are hot and sugar has completely dissolved (or 60 C or 140 F).
  2. Remove egg white and sugar mixture from the heat and- using an electric mixer with a whisk attachment- whip on medium high speed until whites are completely cooled and have formed medium stiff peaks.
  3. Add salt and mix through.
  4. Switch to a paddle attachment and add butter in chunks creaming well between each addition.
  5. When the butter is fully incorporated, and the curdled look changes to a mooth satin look, add the vanilla and whip until completely combined.
Recipe by The Novice Housewife at https://novicehousewife.com/2014/03/24/chocolate-cake-with-rolo-kitkat-filling-and-swiss-meringue-buttercream/