Gather all ingredients and preheat a deep fryer or large saucepan filled with vegetable oil to 375°F (190°C).
In a mixing bowl, whisk together flour, sugar, baking powder, and salt.
Crack in the egg and pour in the milk; whisk until smooth and lump-free.
Working one at a time, dip each Oreo into the pancake batter, ensuring it’s fully coated.
Carefully lower battered cookies into the hot oil using a slotted spoon. Fry for 2–3 minutes, turning once, until golden brown.
Remove to a paper towel–lined plate to drain excess oil.
Dust generously with powdered sugar while still warm.