Sour Cream Coffeecake Muffins

1/2 cup softened butter
1/2 cup sugar
2 eggs
1 cup sour cream
1 tsp. vanilla
2 cups flour
1 tsp. baking powder
1 tsp. baking soda
1/4 tsp. salt

Marble mixture:
1/2 cup brown sugar
1/2 cup finely chopped walnuts
1 tsp. ground cinnamon

Mix together and save 2 tablespoons for top of muffins.

Cream sugar and butter. Add eggs, sour cream and vanilla. Mix in flour, baking powder, soda and salt. Beat well.

With a knife, cut the marble mixture into the batter. Do not mix.

Pour batter into 11 or 12 muffin cups that are well greased. Sprinkle sugar mixture on top.