Steps
- Preheat the oven to 350°F / 180°C. Oil and line two 8in / 20cm round cake pans, with parchment sides at least 2in / 5cm high.
- Mix 500g of all-purpose flour, 2 tablespoons of cocoa powder, 4 teaspoons of baking powder, 2 teaspoons of baking soda, 560g of light brown sugar, and 1 teaspoon of fine salt. Divide equally between two bowls.
- Whisk 300ml of vegetable oil, 400ml of buttermilk, 4 teaspoons of vanilla extract, 30ml of red food coloring gel, 4 large eggs, and 200ml of water. Divide equally.
- Whisk half the wet mixture into half the dry mixture. Divide between the pans; bake for 25-30 minutes, until risen and a skewer comes out clean.
- Cool in the pans for 10 minutes, then unmold onto racks. Reline the pans, mix the remaining wet and dry ingredients, and bake as before. Cool all the layers completely.
- For the frosting, beat 250g of softened lightly salted butter with half of 750g of icing sugar until smooth. Beat in 350g of full-fat cream cheese, 1 teaspoon of vanilla extract, and the remaining icing sugar.
- Stack the cakes with about half the frosting spread between them. Spread the rest over the top and sides.