Raspberry Lemon Muffins

1 1/2 cups flour
1/2 cup sugar
2 tsp baking powder
1/4 tsp salt
1/2 tsp ground cinnamon
1 egg, lightly beaten
1/2 cup butter, melted
1/2 cup buttermilk (or you can substitute milk)
1 cup fresh or frozen raspberries
1 tsp grated lemon peel

Topping:
1/2 cup brown sugar
1/4 cup flour
1 tsp grated lemon peel
1 tsp ground cinnamon
2 Tbs butter, softened

Glaze:
1/2 cup powdered sugar
1 1/2 Tbs fresh lemon juice

Preheat oven to 350 degrees.  Combine 1 1/2 cup flour, sugar, baking powder, salt, and 1/2 tsp cinnamon in a medium bowl.  Make a well in the center of the dry ingredients and add the egg, melted butter, and buttermilk.  Stir just until all ingredients are combined.  Gently stir in the raspberries and 1 tsp lemon peel.  Fill 12 paper-lined or greased muffin cups 3/4 full.  Set aside.  Combine, brown sugar, 1/4 flour, 1 tsp cinnamon and 1 tsp lemon peel.  Cut in butter with pastry blender or use your fingers until crumbly.  Sprinkle mixture over muffins.  Bake 20-25 minutes or until lightly golden brown.  Cool for 20 minutes and glaze with mixture of powdered sugar and lemon juice.