Grew up with this one - it's yummy. I think of it as eating my veggies but getting cake at the same time. A good one to pull on the kids since you can't taste the zucchini but it makes the cake very moist.
Note - on this one you put the topping on BEFORE you bake. But, I have made this without the topping and it was just fine.
1/2 c. margarine
1/4 c. oil
1 3/4c. white sugar
2 1/2 c flour
4 Tb. cocoa
1 tsp. baking soda
1/2 tsp. baking powder
1 tsp. cinnamon
1/2 c. sour milk (which would be just short of 1/2 milk plus 1 1/2 tsp lemon juice)
2 c. zucchini, peeled and grated
1 tsp vanilla
Preheat oven to 325. Cream marg, oil and sugar. Add eggs. Add dry ingredients alternately with sour milk (or, be like me and just dump everything in together). Add zucchini and vanilla. Beat well. Pour into greased 9x13 pan.
1 c chopped walnuts (optional)
1/2 c. brown sugar
1 c. chocolate chips
Mix ingredients and spread evenly on cake before baking. Bake cake at 325 for 40-45 min or until done.