Brownie Bottom Cheesecake

Brownie Bottom:
8 tablespoons margarine
4 squares (1 ounce each) unsweetened baking chocolate
1 1/2 cup sugar
2 eggs
1/4 cup milk
1 teaspoon vanilla
1 cup flour
1/2 teaspoon salt

Preheat oven to 325 degrees. Lightly grease and flour a 9 inch springform pan. Melt margarine and chocolate over low heat, stirring constantly. Remove from heat. Stir in sugar. Cool to lukewarm. Add eggs one at a time, mixing well after each. Blend milk and vanilla in. In seperate bowl combine flour and salt. Stir into chocolate mixture until just blended. Spoon evenly into springform and spead evenly. Bake 25 minutes. Remove.

Topping:
3 - 8 ounce packages cream cheese, softened
3/4 cup sugar
1 teaspoon vanilla
3 eggs
1/2 cup sour cream

Beat cream cheese, sugar, and vanilla until well blended. Add eggs one at a time, mixing well after each. Blend sour cream in. Pour over brownie bottom. Bake 55-60 minutes or until center is almost set. Run knife around rim of pan. Cool before removing rim. Refrigerate 4 hours or overnight. Let cake stand 30 minutes at room temperature before serving.