Preheat your oven to 350°F (175°C) or place a skillet over medium heat.

In a large bowl, whisk together the all-purpose flour, sugar, baking powder, and salt.

In a separate bowl, combine the milk, egg, melted butter, and vanilla extract.

Pour the wet mixture into the bowl of dry ingredients and stir gently until just combined.

Fold in any optional ingredients like fruits or chocolate chips.

Grease a mini muffin tin or add oil to your skillet.

Spoon the batter into the greased muffin cups, filling each about two-thirds full.

Bake for 10-12 minutes or cook in a skillet for about 2-3 minutes on each side until golden.

Cool slightly on a wire rack before serving.