Sensational Cinnamon Coffeecake

1/4 cup butter
3/4 cup sugar
1 egg, slightly beaten
1 1/2 cup flour
2 teaspoons baking powder
1/2 teaspoon salt
1 cup milk
1 teaspoon vanilla extract

Topping:
1 cup brown sugar
3 tablespoons flour
2 teaspoons cinnamon
4 tablespoons butter
1/2 cup walnuts or pecans, finely chopped

Preheat oven to 350 degrees. Spray a 9" x 9" pan with nonstick cooking spray. In a medium bowl, cream margarine and sugar; beat in egg. Sift together flour, baking powder and salt in a separate bowl.

Add to creamed mixture alternately with milk. Stir in vanilla. Pour blended mixture into prepared pan. To make topping: In a small bowl, mix together sugar, flour and cinnamon. Cut in margarine with pastry blender or fork. Spoon half over batter and swirl.

Spoon remaining topping over batter and sprinkle with nuts.

Bake at 350 degrees for 30 minutes.