Chocodeath Cake

Cake batter:
2 cups cake flour
2 teaspoons baking soda
1/2 teaspoon salt
1/2 cup butter or margarine
2 cups granulated sugar
3 large eggs
1 1/2 teaspoons vanilla
3 ounces unsweetened chocolate
1 cup dairy sour cream
1 cup water; boiling

Filling:
1/2 cup butter or margarine
12 ounce caramels
1 can sweetened condensed milk
Preheat oven to 350-degrees. Grease and flour a 9 x 13 pan. Set aside. Sift together cake flour, baking soda and salt. Set aside. Beat butter and sugar together in a large mixing bowl. Blend in the eggs and beat until light and fluffy. Stir in vanilla and melted chocolate. Alternately, add the dry ingredients and the sour cream to the butter mixture. Beat well after each addition. Stir in the boiling water. (batter will be thin). Divide cake batter in half. Pour one half into prepared cake pan. Bake 10-12 minutes or until firm to touch. Remove from oven. Meanwhile, prepare filling. Mix the butter, caramels and sweetened condensed milk in a saucepan and melt over low heat, stirring often.