Maple Brown Sugar Muffins

I love muffins. Who doesn't love muffins? And I ADORE these muffins from Cassie Craves!

Batter:
2 cups all-purpose flour
1/2 cup packed brown sugar
2 tsps baking powder
1/2 tsp salt
3/4 cup milk
1/2 cup butter (melted)
1/2 cup maple syrup
1/4 cup sour cream
1 egg
1/2 tsp vanilla extract

Topping:
 3 tbsp all-purpose flour
2 tbsp sugar
1 tbsp brown sugar
1/2 tsp ground cinnamon
2 tbsp cold butter

Heat oven to 400. In a large mixing bowl combine the flour, brown sugar, baking powder and salt. In a separate bowl combine milk, butter, maple syrup, sour cream, egg and vanilla extract.  Stir the dry ingredients into the milk mixture until combined.  Fill greased muffin tins 2/3s full.  In a small mixing bowl combine flour, sugar, brown sugar and cinnamon.  Cut butter into the mixture.  Crumble the topping over the muffins.  Bake for 16 to 20 minutes.  Cool in pan for 5 minutes. Remove from pan and serve warm.