Start by whisking together flour, baking powder, and sugar in a large bowl.
Melt butter and add to dry ingredients. Add in milk and beaten egg. (If batter is too thick to stir, add little splashes of milk).
Stir all ingredients until combined and fold in blueberries.
Line 12 count muffin tin with muffin liners. Spoon in batter. Bake for 20-25 minutes.