Sour Cream Muffins

This recipe is one of our favorite muffin recipes, maybe because of all the butter and sourcream.  (Although I have used buttermilk if I don't have enough sourcream on hand).  It is from our dear friend Kristy.

5 Tbsp.  butter
1/3- 1/2 cup sugar
1 tsp. vanilla
1/4 tsp. salt
1 cup sour cream
1 egg
3/4 tsp. baking soda
3/4 tsp. baking powder
1 1/2 cup whole wheat flour
1 cup blueberries or apples or...
Bake at 360degrees for 15-18 minutes or less time for smaller muffins