While making the waffle batter, preheat your waffle iron according to the manufacturer directions.
In a large bowl with an electric hand mixer, beat the eggs on medium-low speed until frothy. Add the sugar, then increase the speed to high. Mix until the eggs are voluminous (they should triple in volume), pale yellow, and have thickened slightly, 5-7 minutes.
Beat in the milk, melted butter, oil, and vanilla paste on high just until combined. Add the flour, baking powder, and salt; mix on low speed until just combined, about 30 seconds.
Lightly spray your waffle iron’s cooking surface with nonstick spray. Scoop batter onto the bottom surface. Be sure not to overfill the waffle maker. Close the lid and cook until golden brown; the time for this may vary depending on your waffle maker.
Carefully remove each waffle from the iron; transfer cooked waffles to a baking sheet to keep warm in the oven or transfer to a wire rack to cool completely before refrigerating or freezing.
Continue with remaining batter, greasing the waffle maker with additional oil as needed.
Notes
If you do not have vanilla bean paste, you can substitute pure vanilla extract.