Prep the basics: Line two baking sheets with parchment paper. Set the oven to 350°F (175°C). Make sure butter and cream cheese are truly soft.
Crush the Oreos: Place cookies in a zip-top bag and lightly crush with a rolling pin.
Aim for a mix of fine crumbs and pea-size chunks.
Cream the fats and sugar: In a large bowl, beat butter, cream cheese, granulated sugar, and brown sugar until light and fluffy, 2–3 minutes.
Add egg and vanilla: Beat in the egg and vanilla until smooth, scraping the bowl as needed.
Combine dry ingredients: In a separate bowl, whisk flour, baking powder, baking soda, and salt.
Bring it together: Add dry ingredients to the wet mixture on low speed just until combined. Don’t overmix.
Fold in Oreos: Gently stir in the crushed cookies (and white chocolate chips if using) until evenly distributed.
Chill the dough: Cover and refrigerate for 30–60 minutes. Chilling helps keep cookies thick and prevents spreading.
Scoop and bake: Scoop 2-tablespoon mounds onto prepared sheets, spacing 2 inches apart. Bake 10–12 minutes, until edges are set and centers look slightly underdone.
Cool: Let cookies rest on the sheet for 5 minutes, then transfer to a rack.
They’ll firm up as they cool.