In a large bowl, whisk together all-purpose flour, granulated sugar, baking powder, baking soda, and salt.
Transfer the dry mix to an airtight container. Seal well and label with instructions. You can store this mix at room temperature for up to 6 months.
When you are ready to make pancakes, combine 2 cups of your pancake mix with milk, egg, and melted butter in a bowl. Stir until just combined; a few lumps are fine. Heat a lightly oiled skillet over medium heat.
Pour about 1/4 cup of batter for each pancake and cook until bubbles form on the surface and the edges look set, about 2-3 minutes. Flip and cook until golden brown on the other side, about 1-2 minutes more. Serve warm with your favorite toppings.