Preheat the oven at gas 3.5/ 170° C/ 338°F.

In a mixing bowl, place the flour, cocoa powder, granulated sugar, brown sugar, chilli powder (if using), baking powder, bicarbonate of soda and salt. Stir well using a hand whisk.

Put the milk, oil and eggs in a measuring jug. Lightly beat it using a fork.

Pour the egg mixture into the flour mix, and whisk it using a handheld blender, handheld mixer, or a hand whisk until you get a smooth thick batter.

Then, add the hot coffee into the batter and carefully mix again until the batter is smooth and slightly runny. 

Pour the batter into the prepared pans and gently tap the pans against the kitchen worktop to get the batter surface levelled. 

Bake in the preheated oven at gas 3.5/ 170° C/ 338°F for about 45 minutes or until a skewer comes out clean when you test the cake. 

Once the cakes are fully baked, leave them in the pans for about 2 minutes. Then take them out of the pans and put them on a cooling rack to completely cool down.

Place the cream and the chocolate chips in a mixing bowl. 

Then heat the bowl in a microwave at high-heat (700-800w) for about 1 minute. Give it a good stir. You can see that the chocolate is melting. Mix it until you get as many chocolate chips melted as you can. Heat it again for about 30 seconds if it’s not fully melted. And stir well. 

Or, you can melt the chocolate and cream on a double boiler. Just boil some water in a pot and put the mixing bowl over the boiling water. Let the hot steam melt the chocolate. Stir well until chocolate and cream are mixed thoroughly into a smooth chocolate ganache. 

Leave the chocolate ganache to cool at room temperature. 

Using a hand-held mixer or a stand mixer, whisk the chocolate ganache until you get a smooth and shiny chocolate mousse. Keep it in the fridge to slightly firm. You want the texture to be soft and spreadable. But not hard nor runny. 

Sandwich the cakes with Nutella.

Spread the chocolate mousse to cover the cakes.