1. Cream margarine and sugar until light and fluffy. Add eggs one at a time.
2. Add remaining ingredients, alternating between dry and liquid ingredients.
3. Pour half of batter into greased nine-inch pan. Add either the chocolate or nut filling, following the directions below to finish assembling the cake.
4. Once all the batter has been added to the pan, bake at 350 degrees Fahrenheit for 50 minutes to one hour.