Easy and delicious, this soft Cinnamon Frosted Zucchini Cake Recipe is the perfect sweet dessert any time of year! Tender cake loaded with zucchini and topped with a sweet cinnamon buttercream frosting.
This recipe was originally published in September 2017. I have updated the recipe notes and photos in September 2025.
Aimee’s Recipe Notes
Taste & Texture- Soft, moist zucchini cake with a creamy cinnamon frosting.
Prep Note- Line your baking dish with parchment paper. Before serving, lift the cake out of the pan and cut into bars.
Storage- Keep cake bars in an airtight container at room temperature for up to one week, or freeze for up to 3 months.
Top Tip- store bars in refrigerator and serve chilled. So delicious when cold!
Serving Suggestion- A zucchini bar with a strong cup of dalgona coffee in the morning? Swoon worthy.
Ingredient Notes
Scroll down to the recipe card below for the complete list of ingredients with measurements.
- Brown Sugar – This is the sweetener for the cake bars. I use light brown sugar, but dark brown sugar is fine as well.
- Butter – You need MELTED butter for the cake batter and SOFTENED butter for the frosting. I use and recommend unsalted butter to control the amount of salt in my baking recipes.
- Flour – Regular all-purpose flour works great in this cake. Be sure to measure the flour correctly!
- Shredded Zucchini – Use my guide on how to shred zucchini. Freshly grated or frozen thawed shredded zucchini can be used.
- Vanilla – We love making our own homemade vanilla extract, but if using store bought, be sure it’s PURE extract, not imitation.
How to Make Frosted Zucchini Cake
Make the Zucchini Cake.
- Combine the brown sugar with melted butter. Add in the egg and vanilla. Add in the flour, salt and cinnamon just until combined. Fold in the shredded zucchini.
- Pour cake batter into a parchment paper lined bakind dish.
Frost the Cake Bars.
- Beat the softened butter with powdered sugar, cinnamon and milk, scraping down the sides of the bowl, until fluffy, about 3-5 minutes.
- Spread frosting over cooled cake bars. Cut and enjoy!
Tips and Tricks
- Make sure your zucchini is shredded and not pureed! A box grater works beautifully for shredding zucchini.
- If using FROZEN, thawed zucchini, you’ll want to squeeze out all that excess moisture.
- Beat the softened butter for 3 minutes on its own when making the frosting for a SUPER light and fluffy frosting. Then add the remaining ingredients and beat again until fluffy.
- Allow your bars to cool completely before adding the frosting.
- You can substitute a regular vanilla icing or chocolate sour cream frosting or use a lemon buttercream.
More Zucchini Recipes
- I love zucchini recipes. From easy, moist zucchini bread to the most decadent fudgy zucchini brownies!
- Be sure to add my zucchini crumb cake to your breakfast rotation!
- Nobody will know you didn’t use apples in this easy zucchini crumble recipe.
- If you love chocolate, try my delicious, moist chocolate zucchini cupcakes next.
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Zucchini Cake Recipe
Ingredients
For the cake bars:
- 1 cup light brown sugar packed
- ½ cup unsalted butter melted
- 1 large egg
- 1 teaspoon vanilla extract
- 1 cup all-purpose flour
- ¼ teaspoon kosher salt
- ½ teaspoon cinnamon
- 1 cup shredded zucchini
For the frosting:
- ½ cup unsalted butter softened
- 2 ½ cups powdered sugar
- 1 teaspoon cinnamon
- 3 Tablespoons milk
Instructions
- Preheat oven to 350°F. Line a 9-inch baking dish with parchment paper, set aside.
- In a mixing bowl, combine the brown sugar with melted butter. Add in egg and vanilla. Add flour, salt, cinnamon just until combined. Fold in the zucchini.
- Pour batter into prepared dish. Bake for 26-30 minutes, remove from oven and cool completely before frosting.
- For the frosting, beat butter with powdered sugar, cinnamon, and milk. Scraping down the sides of the bowl, beat until fluffy, about 3-5 minutes. Spread over cooled cake bars. Refrigerate and enjoy!
Notes
Video
Nutrition
Easy Cake Recipes
This recipe is one more reason to keep that garden going for as long as you can. You’ll love these easy, delicious Zucchini Cake Bars so much, you may find yourself buying zucchini all winter long. Enjoy!
Hi, I made these zucchini bars and I have a couple of recommendations. I like my food to have balance. I don’t like one part of it to be drowning out the other tastes. The cinnamon frosting had a bit too much cinnamon for my taste. I would reduce the cinnamon by 25%. The frosting was overwhelming. I frosted the bars and the layer of frosting was thicker than the layer of the zucchini bar. It would be more than enough if you cut the frosting recipe in half. The zucchini bar itself was delicious. I would increase the amount of all ingredients in the zucchini bars by about 25% so that you get a thicker bar.
When you use a complimentary amount o f deliciously flavored frosting, the bars are great.
They really good after refrigerating for several hours.
Hi. Okay, i am not a big zucchini fan, but I have to give these a try!!! Yummy. ????. You only said to squeeze out the water if using frozen so I assume I don’t squeeze out the fresh zucchini, right? Thanks. (I haven’t baked a lot with zucchini)
Love how chewy and gooey these cake bars look:) YUM! I know this is basically blasphemy, but I’m not a big buttercream frosting fan, thinking of doing a hefty layer of a greek-yogurt frosting for some tang, do you think those flavors would would work well here?
MMMMM. Looks SO good! Can’t wait to try.
Swooning over that thick layer of cinnamon frosting! These bars look so delicious!
I like equal parts cake bar and frosting 🙂
Yum! You should really open your own bakery! I bet people tell you that all the time 🙂
Yes! But that sounds like so much work, LOL. Baking in my pajamas and sharing the recipe online is so much easier 🙂