02 The Build
Layer Cake | Peanut Butter, Banana, Chocolate
An Elvis birthday cake for myself. Banana brown-butter sheets, dark chocolate, and salted peanut-butter buttercream, stacked six layers tall.
01 The Idea
For my birthday I made myself the Elvis: peanut butter, banana, and dark chocolate. A banana brown-butter cake carries the fruit, a thin brush of dark ganache does the chocolate, and a salted peanut-butter Swiss meringue buttercream ties it together between every layer and around the whole block.
The recipe I started from was written for round eight-inch pans. I baked it flat on a half-sheet instead, the way I did the strawberry cake, then cut the sheet into bars and stacked them into a tall block. Six bars, stacked, with a light simple-syrup brush and a whisper of ganache under the buttercream on each.
Keep the ganache thin. Between layers this light, a thick one behaves like ice between skates and the cake slides.
A clean peanut-butter-buttercream block, cut to show six layers.
02 The Build
03 The Components
Amounts as I made them. The banana batch fills one 18×12 sheet; the ganache makes more than a thin brush needs, so there is some left over.
one 18×12 sheet
brushed thin between layers
between layers and the coat
a light brush per layer
04 The Method
Brown the butter. Cook the butter over medium until the milk solids are toasty and the liquid is amber. Cool ten to fifteen minutes.
Mix the batter. Whisk the dry: flour, soda, baking powder, salt, cinnamon. In a large bowl whisk the sugars, eggs, vanilla, and lemon until smooth, then whisk in the sour cream, the oil, and the browned butter. Fold in the mashed bananas, then fold in the dry just to combine.
Bake the sheet. Heat the oven to 350°F. Line an 18x12 pan with a single sheet of parchment, light-spray so it stays flat, and anchor the corners with a smear of batter. Scrape in the batter, spread it to the corners, and tap the pan to level. Bake until the center springs back and a skewer pulls moist crumbs, then cool and chill so it cuts clean.
Ganache. Heat the cream, corn syrup, and salt to just steaming. Pour over the chopped chocolate, wait two minutes, then stir from the center out until glossy. Stir in the butter and cool to a soft, brushable state.
Peanut-butter Swiss buttercream. Whisk the egg whites and sugar over a simmering bain-marie to 160°F and fully dissolved. Whip on high to a glossy, room-temp meringue with stiff peaks. On medium, add the butter a few cubes at a time; it may look curdled, keep going until it emulsifies. Beat in the peanut butter, vanilla, salt, and optional PB powder, then mix low a minute to smooth.
Cut into bars. Chill the sheet so it cuts clean. Trim the browned edges and cut into six even bars.
Stack six. For each layer: a light simple-syrup brush, a thin brush of ganache, then a layer of buttercream. Stack six bars, micro-chilling in the fridge after every couple of layers so nothing slides.
Coat. Crumb coat the block and chill fifteen to twenty minutes. Give it a smooth final coat of peanut-butter buttercream, scraped clean into a block. Rest at cool room temp before slicing with a hot, wiped knife.
Baked flat, cut, and stacked
Instead of round pans, I baked the batter as one flat sheet in an 18x12, the same move as the strawberry cake. Chilled firm, it cuts into clean bars that stack into taller, more even layers than a single round would give, and it makes the cross-section the whole point of the cake.
The block is a stack of bars, not a round.