In a large mixing bowl, whisk together the all-purpose flour, granulated sugar, baking powder, baking soda, and salt until well-blended and smooth.

In a separate bowl, combine the milk, large egg, melted butter, and vanilla extract. Whisk until creamy and slightly frothy.

Gradually fold the wet mixture into the dry ingredients using a spatula until just combined.

Preheat your oven to 350°F (175°C) and grease your mini muffin pan.

Fill each muffin cavity about two-thirds full with the pancake batter and bake for 10-12 minutes until puffed and golden brown.

Let the Pancake Poppers cool in the pan for about 5 minutes before removing and serving warm.