Sift flour, sugar, baking powder, and salt together in a bowl.
Combine milk, peanut butter, egg, and oil in a large bowl. Fold in the flour mixture gently until batter is evenly mixed.
Heat a lightly oiled griddle over medium heat. Drop batter by large spoonfuls onto the griddle and cook until bubbles form and the edges are dry, about 2 minutes. Flip and cook until browned on the other side, 2 to 3 minutes. Repeat with remaining batter.