Preheat oven to 350°F (175°C). Line two baking sheets with parchment.
In a bowl, whisk flour, cocoa, baking soda, baking powder, and salt; set aside.
In a mixer, cream butter, granulated sugar, and brown sugar on medium speed until light and fluffy (3–4 minutes).
Add eggs one at a time, mixing until just combined; stir in vanilla.
Reduce mixer to low, add dry ingredients in three parts, mixing until just incorporated.
Fold in chopped Oreos (and white chocolate chips, if using) by hand.
Scoop 2‑Tbsp portions of dough onto prepared sheets, spacing 2″ apart; gently flatten tops.
Bake 10–12 minutes, until edges are set and centers appear slightly soft.
Let cookies rest on pan 5 minutes, then transfer to a wire rack to cool completely.