Preheat the oven to 325°F. Grease a 9-by-13-inch baking pan.
In a small bowl, whisk together the flour, baking powder, baking soda and salt; set aside.
In the bowl of a stand mixer fitted with the paddle attachment, beat the butter and sugars on medium speed until fluffy and creamy. Beat in the vanilla and eggs.
With the stand mixer on low speed, add the dry ingredients, mixing just until incorporated. Add in the Oreos and mix on low speed until cookies are crushed and mixed thoroughly into batter. Spread batter (it will be closer to the consistency of cookie dough) into prepared pan and use a spatula to smooth the top.
Bake for about 40 minutes, until a toothpick inserted in the center comes out clean. Let cool completely before cutting and serving.
Notes
Recipe adapted from Dorie Greenspan's Baking: From My Home to Yours
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.