Nutella Chocolate Cake is a dense and fluffy chocolate mud cake with a creamy Nutella Buttercream filling and topping and finished with Nutella drizzled over top.
Preheat oven to 180°C (350º F).
Line two 20cm (9-inch) round cake pans with baking paper and spray with cooking spray.
In a medium bowl, combine the oil, milk, eggs and vanilla extract and mix together.
In a large bowl, combine the flour, sugar, cocoa powder, salt, baking soda, and baking powder.
Add the wet ingredients to the dry and mix either by hand or on a low speed of a hand mixer. Don't over-mix.
Add the water and combine. The batter will be thin.
Pour the batter into both of the pans and bake for 30-40 minutes or until a toothpick poked into the center comes out clean. Cool for 10 minutes before removing cakes from the pans.
Allow to cool completely before filling and icing.
Beat the butter and the Nutella together.
Slowly beat in the icing sugar and milk.
Add more milk as needed until you have a thick and spreadable consistency.
Slice both cakes in half so you now have four cakes.
Its optional, but highly recommended, to spread two tablespoons of Nutella on each layer before spreading buttercream on the the layers and stacking until you have a four layer cake.
Now you can spread the remaining Nutella Buttercream on top of the cake and the sides. I went for a more 'naked cake' look on the sides so I could decorate the top of the cake but the decorating is up to you!
Sprinkle over any remaining Nutella on top and you're done!