Sift together flour, baking powder, soda, salt, and spices and set aside. In a bowl beat together the oil and sugar and lemon zest for 2 minutes; add eggs one at a time, stopping to scrape down the sides. Turn mixer to low and add dry ingredients in two batches, mixing slowly until well-blended. Add zucchini, buttermilk, and lemon juice and mix in, then separate into the three baking pans and bake 24 to 26 minutes. Let cool.