To prepare a zucchini bars with spice frosting recipe, you'll need: Zucchini, sugar, flour, baking powder, salt, cinnamon, nutmeg, ginger, vanilla extract, buttermilk, eggs, oil and vanilla. Preheat the oven to 350 degrees F (180 degrees C). Grease and flour two 9x9-inch baking pans and set aside. Cut the zucchini in half lengthwise and scoop out the seeds. Place the cut-side down on the greased pan. Bake in the preheated oven for 20 to 25 minutes or until the edges are golden brown. Remove from oven and allow to cool for 5 minutes before slicing into bars.