To make the cupcakes, preheat the oven to 350 degrees and line a muffin pan with cupcakes liners. Sift together the flour, cocoa powder, baking soda, baking powder, and salt. In a large bowl, beat the eggs and sugar for 3-5 minutes or until the mixture is pale and thick. Add in the butter and beat until combined. Then, add in the nutella. Add the flour mixture and milk half at a time until well-blended. Finally, add the chocolate chips.
Divide batter into the cupcake liners, filling 2/3 full. Bake about 25 minutes or until a toothpick inserted in the center comes out clean. Remove from the oven and let cool completely. The centers may sink in a little, but that’s okay since we’re going to remove them for the filling anyway. Once cooled, use a knife to cut a hole in the center of each cupcake and then scoop out the cake.
To make the nutella filling, whip the cream until stiff peaks form. Beat in the nutella.
Scoop the filling into a piping bag and pipe into the center of each cupcake.
To make the frosting, beat the butter until smooth. Add in the powdered sugar gradually until all of it has been incorporated, and then beat in the nutella. The "I'm too tired from doing all the other steps" alternative: purchase pre-made Buttercream icing and mix in Nutella to taste. Decorate the cupcakes as desired.