Preheat the oven to 425 degrees F.
Mix the pancake ingredients together in a large bowl. Stir gently, being careful not to overmix. The batter will have some small lumps in it. Stir in fillings if desired.
Grease a 15 ½ by 10 ½ by 1-inch baking sheet (a half-sheet pan) with oil or butter. Pour the pancake batter onto the sheet pan.
Bake the pancakes in the oven for about 10 minutes or until the pancakes look golden brown on top. Remove from the oven, allow to cool slightly, and slice into squares. Use a flat metal or plastic spatula to lift each pancake off the pan.
Serve with desired toppings.