This is a delicious and easy cake with ingredients that are probably already in your pantry. It's quick to make, and very tasty. Although making brown butter can seem kind of daunting, it's actually very easy. I put chocolate shavings on this one, but you can top it with whatever you want (nut brittle, caramel, ice cream, etc.), but it's also great by itself. Enjoy!
Step 1: The Cake
1/2 cup (45 g) dutch processed cocoa powder
3/4 cup (180 ml) boiling water
1 1/2 cups (212 g) all-purpose flour
1 cup (200 g) granulated sugar
1/2 tsp baking soda
1/2 tsp baking powder
1/2 tsp salt
1/2 tsp instant espresso powder
1/3 cup (75 ml) vegetable oil
1 large egg
1 tsp vanilla extract
Adjust oven rack to middle position, and preheat oven to 350 F/180 C. Grease an 8"x8" (20x20 cm) square pan with cooking spray or butter, line the bottom with parchment paper, and grease the paper. Set aside.
Whisk together the cocoa and boiling water, and set aside to cool slightly.
In a large bowl whisk together the flour, sugar, baking soda, baking powder, salt, and espresso powder. In a separate bowl whisk together the oil, egg, vanilla, and cooled cocoa mixture. Stir the oil mixture into the flour mixture and whisk until smooth. Give the mixture a final stir with a rubber spatula to make sure it is fully combined. Scrape batter into the prepared pan, smooth the top, and rap against the counter a few times to make sure there are no large air bubbles.
Bake for 20-25 minutes or until a toothpick inserted into the center comes out with a few crumbs attached.
Let the cake cool for about 10 minutes in the pan, then run a knife around the outside and unmold onto a wire rack to cool completely.
Recipe adapted from America's Test Kitchen.
Step 2: The Frosting
8 oz (230 g) milk chocolate (chips or chopped)
8 tbsp (113 g) unsalted butter
2 tbsp (1/2 oz) dry milk powder (optional)
1/4 cup (30 ml) half and half
Place chocolate in a medium bowl and set aside. Heat butter in a saucepan over medium-low heat. When melted, stir in the milk powder. Cook until the milk solids start to brown to the color of toast. Remove from the heat and stir in half and half. Pour over chocolate while still very hot. Let sit 2-3 minutes to melt chocolate, then stir until combined. Cover with plastic wrap and let set at room temperature (or place in the fridge until about half the mixture is firm). When set, stir until smooth. Use immediately.
Note: If you do not have dry milk powder, you can leave it out. In brown butter, it's the milk solids that darken and give it flavor. Since dry milk is basically all milk solids, it will give the frosting a much stronger flavor. However, it will still work if you choose to leave it out, the flavor will just be milder.
Step 3: Assembly
To assemble the cake, your frosting still needs to be freshly mixed, or it will set up so much that it could rip the cake. You can frost top and sides if you like, or just the top like I did. To get the frosting swirls, drag and lift the back of a spoon over the top. I topped it with chocolate curls (made by microwaving a chocolate bar until it softened a little without melting, and then dragging a knife along the back) and crunchy salt. Although it looks extra impressive with some topping, it's equally delicious without. Enjoy!