Blueberry Muffins - Great for a lazy Sunday!

I did not create this recipe and I have no idea who to give the credit to for it because I have used it for SO long now.  All I can say is I pulled it from a magazine probably 15 years ago.  Thank You to whomever created it because I love it and I'm passing it on hoping others will too.
This recipe makes 1 dozen muffins.

2 Cups all purpose flour
1/2 Cup Sugar
3 teaspoons baking powder
1/3 teaspoon salt
1/2 cup cold butter
1 egg
3/4 Cup milk
1 teaspoon grated orange peel
1 teaspoon vanilla extract
1 cup fresh or frozen blueberries

Topping
1/3 cup brown sugar
2 tablespoons flour
2 tablespoons cold butter

In a large bowl, sift together the flour, sugar, baking powder and salt.  Cut in butter until mixture resembles coarse crumbs.  In another bowl, combine the egg, milk, orange peel and vanilla;  stir into crumb mixture just until moist.  Gently fold in blueberries.

For topping mixture combine ingredients, cut in the cold butter and mix until it resembles coarse crumbs.

Fill paper lined muffin cups 2/3 full.  Sprinkle on about 1 teaspoon of topping over muffins.

Bake at 375 for 20-25 minutes.

ENJOY!!