Cream together the first four ingredients. Mix the dry ingredients together and add to the creamed mixture with the vanilla, zucchini and soured milk. Mix well, about 3 minutes. Grease and flour bread pans or a 9"x13" cake pan. Pre-heat oven to 325°F.
Fill prepared pans 3/4 full and sprinkle with the chopped nuts and chocolate chips. Bake the cake for 45 minutes and the mini loafs for 30 minutes or until cake tester comes out clean. Let cool in pan for 5 minutes and turn out mini loafs to cool on cooling racks. Let cool completely. Wrap in plastic wrap and can be frozen for up to 6 months.
I also like to add 1 cup of nut meats to the zucchini batter before baking.