In a medium mixing bowl, whisk the egg, milk, butter (or oil), and vanilla extract.
Over the wet ingredients, add flour, sugar, baking powder, and salt.
Lightly whisk the dry ingredients before mixing them fully into the wet ingredients so the baking powder can be dispersed
Place Oreo Cookies into a large zip-tight bag and crush them with a rolling pin
Fold the Oreo Cookies into the batter.
Heat a skillet over medium heat. Add some butter to the warm skillet to melt.
Scoop 1/4 cup of batter over the butter and spread into a circle.
Cook each side for about three minutes on one side, then flip. Continue to cook a couple of more minutes until the pancakes are golden brown and cooked through.