In a small bowl mix together the heavy cream and the egg. To it add the nutella and whisk it in. Pour the cream mixture into the dry ingredients and using a fork start to work the wet ingredients into the dry ingredients until the dough comes together. Add in the pecans and knead it a few times until the dough stays together.
In a large bowl mix together the flour, cocoa powder, sugar, baking powder and salt. Using a pastry blender cut in the butter until your mixture resembles pea sized crumbles.
Preheat oven to 375 F degrees. Line a baking sheet with parchment paper.