1. Preheat the oven to 350F. Lightly grease and line a 9×5-inch loaf pan with parchment paper.
2. In a large bowl, combine the flour, baking soda and salt.
3. In the bowl of a stand mixer with the paddle attachment (or hand held mixer), cream on medium speed, the butter, light brown sugar and sugar until soft and creamy.
4. Add in eggs, mashed bananas and vanilla mixing on low as you go.
5. Add the wet mixture to the dry ingredients, mix using a spatula until fully incorporated.
6. Transfer about half of the mixture to a separate bowl. Melt the Nutella in the microwave for about 10-15 seconds; you’re looking for a runnier more spreadable texture. Add Nutella and cocoa to the mixture and combine.
7. Transfer both mixtures to prepared pan.
8. Bake for 60-65 minutes. Allow to cool in the pan for 10-15 minutes before transferring to cooling rack.

For the Chocolate Buttercream:

1. In the bowl of a stand mixer, fitted with he paddle attachment, beat the butter, medium speed, until soft and creamy, about 2 minutes. Reduce speed to low, add the sifted confectioners sugar, cocoa powder, 1-2 tablespoons of milk at a time, vanilla and salt. Beat for about 5 minutes until smooth. If the buttercream is too thick, add 1 tbsp of milk at a time, until desired consistency.

Assemble:

1. Spread the buttercream on top using an angled spatula or back of a spoon when ready to serve. Enjoy!