In a large mixing bowl, whisk together the flour, sugar, baking powder, baking soda, and salt until evenly combined.
In a separate bowl or large measuring cup, whisk together the buttermilk, egg, melted butter, and vanilla extract until smooth.
Pour the wet ingredients into the dry ingredients and stir gently with a rubber spatula just until the flour disappears. The batter will be lumpy — do not overmix.
Gently fold in about three-quarters of the crushed Oreos, reserving the rest for topping. Let the batter rest for 5 minutes while you heat the griddle.
Heat a griddle or large nonstick skillet over medium heat (325-350°F). Lightly grease with butter or cooking spray.
Pour 1/4 cup batter per pancake onto the griddle, spacing them 2 inches apart. Immediately press a few reserved Oreo pieces into the top of each pancake.
Cook until bubbles form on the surface and the edges look set, about 2-3 minutes. The bottoms should be golden brown with slightly darker cookie spots.
Flip carefully with a wide spatula and cook the second side until golden and cooked through, another 2 minutes. The centers should spring back when gently pressed.
Transfer to a plate and repeat with remaining batter, re-greasing the griddle between batches as needed.
Serve immediately topped with whipped cream, extra crushed Oreos, chocolate syrup, or maple syrup.
