Baking powder and baking soda is my guess.
Here is the recipe I like to use.
Ingredients:
1 cup all-purpose flour
2 teaspoons baking powder
1 teaspoon baking soda
1 teaspoon sugar
1/2 teaspoon salt
3/4 cup buttermilk
1/2 cup milk
1 large egg
2 tablespoons butter, melted and cooled
1. Whisk together first 5 ingredients in a large bowl. Combine buttermilk, milk, egg, and butter in a separate bowl; add to flour mixture, and whisk just until blended. Transfer to a large measuring cup, and let stand 10 minutes.2. Pour 3 to 4 tablespoons of batter onto a hot, lightly greased griddle or nonstick pan. Cook until pancakes are covered with bubbles and edges turn brown. Turn and cook other side 2 minutes or until golden brown.
Good luck, best wishes and pass the eggs please.