Preheat oven to 350°F. Line an 8 x8 baking pan with parchment paper. In a small bowl, stir together flour, baking soda, and baking powder. Set aside.
In a large bowl, cream together the butter and sugar until smooth. Beat in egg and vanilla. Gradually blend in the dry ingredients until dough is formed.
Remove half the dough and set aside. Add crushed Oreos into the dough remaining in the mixer and mix until oreo cookies are mixed throughout the dough. Remove cookies and cream dough and set aside.
Put back in the remaining dough and add in 1/2 cup Nutella. Mix on medium speed until Nutella is completely mixed into the dough. Put dough into baking pan. Press down and spread until it evenly covers surface of pan. Place cookies and cream dough on top and do the same.
Bake about 20 minutes in the preheated oven, or until the top begins to turn golden. Cool before cutting and serving.
The nutrition information provided are only estimates based on an online nutritional calculator. This is not a comprehensive list of all the nutrients in the recipe (i.e., does not include vitamins, cholesterol, etc). I am not a certified nutritionist. Please consult a nutritionist or doctor for accurate information and any dietary restrictions and concerns you may have.