Preheat oven to 375℉. In a large mixing bowl, mix together your dry ingredients of 2½ cups flour, 1 tbsp baking powder ½ tsp salt, and 2 tbsp granulated sugar.
With a cheese grater, grate your cold butter and mix into dry ingredients with your hands or mixing spoon until it reaches a mealy texture.
In a separate bowl, whisk together 1 egg, 1 cup buttermilk and 1 tsp vanilla. Add to the bowl of dry ingredients and mix until just combined.
Fold in 1½ cups white chocolate chips and 1½ cups crushed Oreo cookies; you want the dough to be just sticky enough to stick to your hands. Add more buttermilk 1 tbsp at a time if you feel are too dry. Spread into a circle onto a baking sheet and cut into serving sizes, the same way you would a pizza.
Bake for 22-30 minutes until center is set and edges are golden. Top with crushed Oreo cookie or if desired a glaze of ¼ cup powdered sugar and 1 tbsp milk.