Steps
- Preheat the oven to 350°F / 175°C. Grease and line a 9 × 9in / 23 × 23cm baking pan with parchment paper. Measure 1 tablespoon of vanilla extract.
- Beat ⅔ cup of melted butter, ⅔ cup of brown sugar, 1 cup of all-purpose flour, ¼ cup of cocoa powder, one-third of the vanilla, and 1 extra-large egg until smooth. Spread in the pan.
- Mix 397g of sweetened condensed milk, 2 cups of finely shredded unsweetened coconut, and one-third of the vanilla. Drop spoonfuls over the batter and gently spread level.
- Bake for 25-30 minutes, until set. Cool completely.
- Beat 2 cups of icing sugar, 3 tablespoons of cocoa powder, one-third of the vanilla, ¼ cup of butter, and 2 tablespoons of milk until spreadable, adding a little more milk if needed.
- Spread the frosting over the cooled slab and cut into squares.