Preheat the oven to 400°F (200°C). Grease the muffin tins.

Melt the butter, then add the milk and the beaten egg. Mix well.

In a mixing bowl, combine the flour, sugar, baking powder, and salt. Add the wet mixture to the dry ingredients.

Mix until you have a smooth batter.

Fill the muffin tins about 3/4 full and bake for about 18 minutes. Let cool for a few minutes before removing from the tins.