Mix 250g brown sugar, 160ml buttermilk, 160ml vegetable oil, 120g plain yogurt, 2 eggs, and 1 tsp vanilla
Sift in 280g flour, 1 tsp baking powder, 2 tsp baking soda, and ½ tsp salt
Stir 50g cocoa and 1 tbsp coffee into 250ml hot water and mix into batter
Pour into a 13"x10" tray and bake at 180°C for 30-35 minutes
Simmer 120ml milk and 120ml whipping cream
Whisk 2 eggs, 1 yolk, and 25g sugar, then slowly whisk in the hot milk
Cook on low until it coats a spoon
Pour over 200g dark chocolate and stir until smooth, then chill
Beat 250g cream cheese, 15g cocoa, and 30g powdered sugar
Gently fold in 120ml whipped cream
Cut cake into 4"x8" rectangles and slice layers horizontally
Layer cake, cremeux, cake, and cream cheese filling
Chill in fridge for 4 hours
