Step 1

Heat oven at 340°F/170°C on bottom heat (turning off the convection setting). Place an 8x8-inch square baking pan directly on the bottom of the oven, and let heat for 8 to 10 minutes.

Step 2

In a small pot, warm coconut milk over low heat to 115°F/45°C. Whisk in the instant yeast and set aside for 5 minutes. In a large bowl, add tapioca starch, flour, light brown sugar, salt, whole eggs, and egg yolks. Pour in the coconut milk and yeast mixture, and whisk until absolutely lump-free. Cover and let sit for 1 hour until very foamy on the surface.

Step 3

Meanwhile, make the bacon. Place the bacon on a plate in a single layer, sandwiched between two pieces of paper towels. Microwave on high for 4 to 5 minutes until crispy, set aside. In a spice grinder, grind the pre-frozen roasted peanuts (this prevents them from releasing oil and turning into peanut butter) and dark brown sugar until finely ground, set aside.

Step 4

Mix baking soda, baking powder and 1 ½ tablespoons water and add to the foamed batter, whisk to combine. Brush the surface of the heated brownie pan with a bit of the softened butter, then pour the batter in through a sieve. Skim off as much foam on the surface with a spoon as you can but no need to be perfect. Return the pan directly to the bottom of the oven. Bake for 20 minutes, constantly checking on the cake. If it’s browning faster on one edge than the other, rotate the pan. If the edges are turning golden brown before 20 minutes are up, turn down the heat a bit. In the end, the batter should be set, with holes throughout (if you can only see holes around the edges with the center of the cake bulging up with no visible holes, it’s fine too).

Step 5

Move the pan to an upper rack (turn the oven setting to top heat, or browning setting, if possible), and bake for another 5 to 10 minutes until the surface is lightly browned. Remove from the oven.

Step 6

Score the edges with a small knife and transfer the cake out of the pan and onto a cooling rack. If your cake has bulged up in the middle and you can’t see any holes, use a serrated knife to slice off the top surface to expose the holes underneath and make the cake more even. Spread the remaining softened butter over the top and let it melt into the holes while the cake is still hot. Sprinkle the peanut sugar evenly across the surface, then arrange the bacon on one half of the surface. Peel and roughly smash the banana and arrange it on the other half of the surface.

Step 7

Use a serrated knife and trim off the four edges of the cake. Cut it in half along the bacon and banana line, then invert and banana side over the bacon side to make a sandwich. Cut into 4 pieces and serve.