Preheat the oven to 350°F. Grease an 8x8-inch baking pan with non-stick cooking spray or line with parchment paper. Set aside.
In a mixing bowl, mix together the dry ingredients: flour, sugar, baking powder, baking soda, and salt. Set aside.
In another bowl, whisk together the melted butter, egg, and vanilla extract. Then, add milk and whisk until combined.
Whisk in the dry ingredients just until combined. The batter should be lumpy. Don’t overmix it.
Pour the pancake batter into the prepared baking pan. Bake for 15-20 minutes, or until a toothpick inserted in the middle comes out clean. Remove from the oven and let the pancake squares cool slightly in the baking pan. Slice into squares and serve warm with your favorite pancake topping (berries, fruits, honey, or maple syrup). Enjoy!