Preheat oven to 180°C. Grease a 21cm × 21cm square cake pan and line with baking paper.

Place a box of Dr. Oetker Nona Signature Moist Cake mix, 60ml water, 150ml oil and 3 eggs in a mixing bowl. Mix on low speed until ingredients are combined, then mix at high speed for another 3 minutes. Pour batter into cake pan.

Bake at 180°C for 55 minutes. Cool for 5 minutes before removing from pan. Invert the cake onto a cooling rack and set aside.

For the frosting, mix cocoa powder with whipping cream at medium speed until soft peaks form.

In a separated mixing bowl, whisk the dark chocolate icing mix, softened butter and boiling water until well combined.

Spread the frosting on top of the cake, decorate with desire topping and drizzle with dark chocolate icing.