Preheat the Belgian Waffle Maker: Turn on your Belgian waffle maker and allow it to heat according to the manufacturer's instructions.
Prepare the Dry Ingredients: In a large bowl, whisk together the flour, sugar, baking powder, and salt.
Mix the Wet Ingredients: In a separate bowl, whisk together the eggs, milk, vegetable oil (or melted butter), and vanilla extract.
Combine Wet and Dry Ingredients: Gradually pour the wet ingredients into the bowl with the dry ingredients. Then, gently mix until combined. It's okay if the batter is slightly lumpy; overmixing can make the waffles tough.
Grease the Waffle Maker (if needed): If your waffle maker isn’t non-stick, lightly grease it with cooking spray or brush with melted butter.
Pour the Batter: Ladle enough batter onto the center of the waffle maker to fill the grid, usually about ¾ cup, depending on the size of your waffle maker. Do not overfill.
Cook the Waffles: Close the lid and cook according to the waffle maker's instructions, typically 4-5 minutes, or until the waffles are golden brown and crisp.
Remove and Serve: Use a fork or tongs to carefully remove the waffle. Serve immediately or place on a wire rack to keep crispy.
Repeat: Repeat the process with the remaining batter.