Sift together flour, baking powder, sugar, and salt.
In another bowl, whisk together the eggs and 1 1/2 cups of milk. Add to flour mixture, stirring only until smooth.
Combine peanut butter and melted butter. Blend in mixture.
If the batter seems too thick to spread, add a little more milk.
Cook on a hot, greased griddle, using about 1/4 cup of batter for each pancake.
Cook until bubbly and somewhat dry around the edges, and lightly browned on the bottom; turn and brown the other side.