Combine shortening and butter in a large mixing bowl; mix well. Gradually add sugar, beating until light and fluffy. Add eggs, one at a time, beating well after each addition.
Combine flour, salt, and baking powder; add to creamed mixture alternately with milk, beginning and ending with flour mixture. Mix well after each addition. Stir in flavoring.
Pour batter into a well greased 10-inch tube pan. Bake at 325° for 1 hour and 20 minutes or until cake tests done. Cool in pan 10 to 15 minutes; remove from pan, and cool completely. Spread Brown Sugar Frosting over top of cake.