Preheat oven to 300 degrees F (150 degrees C). Grease and flour two 8 inch, round, cake pans.
Cream butter or margarine in a large mixing bowl. Gradually add sugar, beating well. Add eggs one at a time, beating mixture well after each addition.
Dissolve soda in buttermilk, stirring well. Mix flour into creamed mixture alternately with buttermilk mixture, beginning and ending with flour. Mix well after addition. Stir in crumbled mincemeat. Spoon batter into prepared pans.
Bake for 45 to 50 minutes, or until a wooden pick inserted in center comes out clean. Cool cake in pan for 10 minutes. Remove layers from pans, and cool completely. Fill and frost the cake with Caramel Cream Frosting.