With 2 knives cut in 6 tbsp. butter until mixture resembles coarse crumbs. Briefly rub the mixture between fingers to blend the butter. Set aside.
Preheat oven to 400 degrees F and grease 12 muffin cups.
In a large bowl; with an electric mixer beat butter & sugar until light and fluffy. Add egg and beat until well blended.
In a medium bowl, combine flour, baking soda, baking powder, cinnamon, and salt. In a small bowl, combine milk, sour cream, and vanilla. Add flour mixture to butter mixture. Alternately with the milk mixture beating just until batter is combined. Gently fold in raspberries (or other berries of your choice).
Spoon into tins about 2/3 full. Sprinkle with the topping.
Bake in a preheated oven for 20-25 minutes. Cool 5 minutes and remove.