Preheat oven to 350°F (180°C)
Grease a 9 inch (23 cm) cake tin
Mix flour, cocoa powder, baking powder, salt, sugar and vanilla essence in a large bowl.
Add milk, butter and eggs.
Mix everything together by using an electric mixer at slow speed, until it’s smooth. If the batter is too runny you can add a little more flour.
Transfer to bake tin and bake at 350°F until a toothpick inserted in center comes out clean, about 40 minutes.
Take it out and let it cool for about 20 min.
After the cake has cooled, slice it through the middle to make two layers. You can either use a long sharp knife or a thread to cut it.
Mix the heavy cream for about 3 min, till it’s hard, then add nutella. Mix for another min, untill it’s smooth.
Use one 1/3 of the frosting between the two layers, 1/3 on top, and the rest around the cake.
Decorate the cake with your favorite cake decorations and store in the refrigerator.