To prepare a zucchini bars recipe, you'll need: Zucchini, sugar, flour, baking powder, salt, cinnamon, nutmeg, vanilla, zucchini puree, buttermilk, eggs, and vanilla extract. Preheat the oven to 350 degrees F (180 degrees C) and grease an 8x8x2-inch baking pan with non-stick cooking spray. Cut the zucchini in half lengthwise and scoop out the seeds. Place the squash halves in the prepared pan and bake for 20 to 25 minutes, or until browned. Remove from oven and let cool for 5 minutes before slicing.