Blueberry Lemon Muffins

This is a recipe from the Sisters Cafe. They have a great blog with lots of good recipes. I was looking for a muffin to make for friends and I saw this. Anything labelled "Grandma's Famous" is a must make!

Ingredients
2 cups flour
1/2 cup sugar
3 tsp baking powder
1/2 tsp salt
zest of one lemon
1 egg
1 cup milk
1/2 cup butter
1 cup frozen blueberries

Topping (this is what makes these so special!):
1/4 cup butter, melted
1 Tb lemon juice
1/2 cup sugar

Mix dry ingredients(except sugar) and set aside. Beat butter and sugar. Add egg. Add dry ingredients and lemon zest alternating with milk. Gently stir in the blueberries. Bake at 375 degrees for 20-25 minutes. Combine butter and lemon juice. While the muffins are still warm, dip the tops in the butter and lemon juice, then dip in sugar. Makes 12 muffins.