Step 1

Preheat oven to 350F, grease three 6" round baking pans and dust with cocoa powder. Line bottoms with parchment.

Step 2

Place all dry ingredients into the bowl of a stand mixer fitted with a paddle attachment. Stir to combine.

Step 3

In a medium bowl whisk all wet ingredients (pour water in slowly as not to cook the eggs if very hot).

Step 4

Add wet ingredients to dry and mix on medium for 2-3 mins. Batter will be very thin.

Step 5

Pour evenly into prepared pans. I used a kitchen scale to ensure the batter is evenly distributed.

Step 6

Bake until a cake tester comes out mostly clean. A total of 35-40mins.

Step 7

Cool 10 minutes in the pans then turn out onto a wire rack to cool completely.

Step 8

Place egg whites and dark brown sugar into the bowl of a stand mixer, whisk until combined.*

Step 9

Place bowl over a hot water bath on the stove and whisk constantly until the mixture is hot and no longer grainy to the touch (approx. 3mins). Or registers 160F on a candy thermometer.

Step 10

Place bowl on your stand mixer and whisk on med-high until the meringue is stiff and cooled (the bowl is no longer warm to the touch (approx. 5-10mins)).

Step 11

Switch to paddle attachment. Slowly add cubed butter and mix until smooth.**

Step 12

Add powdered peanut butter 1 Tbsp at a time. Add vanilla and whip until smooth.

Step 13

Place one layer of cake on a cake stand or serving dish. Top with about 2/3 cup buttercream. Repeat with remaining layers. Frost and smooth the outside with a thin crumb coat (thicker on the very top). Chill for 20mins.

Step 14

Do a decorative rope border on top using a 1M tip if desired.***