Step 1

Make a pudding with pudding powder, milk and sugar (note: you actually need only 400ml of milk and therefore less milk than the instructions say!) Pour the pudding into a bowl and let it cool down at room temperature. While cooling, stir again and again or cover with cling film so that no skin develops.

Step 2

Place the softened butter, which must be at room temperature like the pudding, in a bowl. Using a stand mixer or hand mixer and whisk, beat the butter and powdered sugar for a few minutes until very light and fluffy. Slowly stir in the pudding, tablespoon by tablespoon, until everything forms a homogeneous cream. Either decorate or fill the cake directly with a spatula or chill the buttercream briefly beforehand so that it becomes a little firmer.