01 - Preheat oven to 375°F. Line a 12-cup mini muffin pan with paper liners or lightly coat with cooking spray.
02 - In a medium mixing bowl, whisk together flour, sugar, baking powder, baking soda, and salt until thoroughly blended.
03 - In a separate bowl, whisk milk, egg, melted butter, and vanilla extract until combined.
04 - Add wet mixture to dry ingredients and stir gently until just incorporated. Do not overmix; small lumps are acceptable.
05 - Fold in desired add-ins such as chocolate chips, fruit, or sprinkles, if using.
06 - Drop batter evenly into muffin cups, filling each about three-quarters full.
07 - Bake for 12 to 15 minutes until golden and a toothpick inserted in the center of a muffin emerges clean.
08 - Let muffins rest in the pan for 5 minutes, then transfer to a wire rack. Enjoy warm, optionally with maple syrup for dipping.