Place flour, cocoa powder, baking powder and salt into a medium-sized mixing bowl. Whisk together and set aside.
Mix butter and cream cheese in a large mixing bowl with an electric hand mixer. Add sugar to the bowl. Cream the butter, cream cheese and sugars together for about 1 to 2 minutes. Add eggs and vanilla extract and mix for another minute. Add nutella and beat for another minute. Add flour mixture in two batches and mix with rubber spatula until incorporated. Refrigerate cookie dough for 4 hours.
Heat oven to 350°F. Using a 1 1/2 Tablespoon cookie scoop, portion out dough and roll into balls. Roll in powdered sugar until it's completely covered. Bake on a baking sheet covered with parchment paper for about 13 to 14 minutes. Pull parchment paper from baking sheet with cookies and place on wire cooling racks. Allow to cool completely before storing in an airtight container.