These Zucchini Brownies are rich, chocolaty, and made with no eggs. These delicious brownies made with fall's favorite squash will be made all year long.
In a large mixing bowl or stand mixer, add all of the ingredients and mix until well combined. The batter will be thick and a little dry, which is okay.
Pour into a 9x13 baking pan. Bake for 20-25 minutes or until toothpick inserted into the center comes out clean. Remove from oven and cool on baking rack.
Once brownies are cooled prepare frosting.
In a medium glass mixing bowl add butter and cover with a plate and heat butter for 1 minute in the microwave. Remove from microwave and remove lid. Stir in vanilla and buttermilk, place back in the microwave and heat for 30 seconds, stir, then heat for another 30 seconds, stir, heat for 30 seconds and stir and then heat for another 30 seconds.
Remove from microwave and stir in cocoa and powder sugar, until well combined. Place back in the microwave and heat for 30 seconds, stir. Heat for another 30 seconds and stir, repeat 1 more time if needed, until frosting is smooth and there are no clumps. Pour over brownies, and spread evenly. Let frosting cool and harden.