Lemon Blueberry Maple Muffins

2 1/4 cups flour
2 1/2 tsp baking powder
1/2 tsp salt
1 cup maple sugar
2 eggs, room temperature 
1/4 cup milk
1/4 cup sour cream
2 tsp Lemon extract
1/2 cup maple syrup
2 cups of blueberries
Bake at 350° for 35 minutes
Sprinkle with maple sugar