Your oven should be preheated to 375°F (190°C). Spray a large sheet pan with non-stick cooking spray.
In a large mixing bowl, whisk together the flour, baking powder, salt and granulated sugar just until dry ingredients are evenly mixed.
Make a well in the center of the dry mixture. Add the milk, beaten eggs, vanilla extract, and oil or melted butter. Gently stir until the mixture is just combined — overmixing can lead to a denser texture. It’s all right if you have a few lumps in the batter.
Spread the prepared batter into the bottom of the prepared sheet pan, coming all the way to the edges. If using, sprinkle your chosen add-ins evenly across the surface.
Put the sheet pan in the preheated oven and bake until 12 to 15 minutes. A pancake is ready when its center is set and no longer jiggles, the edges are lightly golden.
Take out from the oven, let cool slightly and cut into squares. Serve warm with garnishes of your choice.
