Get ready to transform a humble summer vegetable into the most talked-about dessert on the block. If you think zucchini only belongs in savory dishes, this recipe will change your mind forever. We’re talking about incredibly moist, perfectly spiced zucchini bars baked to tender perfection and slathered with a rich, buttery, and utterly decadent caramel frosting. It’s the perfect combination of a comforting spice cake and a sweet candy shop confection. This is, without a doubt, the most delicious way to use up that garden zucchini!

Why You Will Fall in Love with These Bars

This recipe is a true standout, and here’s why it deserves a permanent place in your recipe box:

Unbelievably Moist: The grated zucchini adds a secret weapon of moisture that keeps these bars tender and delicious for days.
Perfect Spice Blend: Warm notes of cinnamon and nutmeg create a cozy, comforting flavor that perfectly complements the sweet caramel.
Irresistible Frosting: The homemade caramel frosting is the star of the show. It’s buttery, sweet, and sets into the perfect fudgy layer.
Easy & Crowd-Pleasing: This simple sheet-pan recipe is easy to whip up and serves a crowd, making it perfect for parties, potlucks, or family gatherings.

Gather Your Ingredients

This recipe is broken down into two simple parts: the bars and the frosting.

For the Moist Zucchini Bars:

2 cups grated zucchini (no need to peel!)
1 ½ cups all-purpose flour
1 tsp baking soda
½ tsp salt
1 ½ tsp ground cinnamon
¼ tsp ground nutmeg
½ cup granulated sugar
½ cup brown sugar, packed
2 large eggs
½ cup vegetable oil
1 tsp vanilla extract

For the Dreamy Caramel Frosting:

½ cup unsalted butter
1 cup brown sugar, packed
¼ cup milk (whole milk or 2% works best)
2 cups powdered sugar
1 tsp vanilla extract
A pinch of salt (optional, but recommended to balance sweetness)

Step-by-Step Instructions to Dessert Heaven

Let’s bake these incredible bars. Follow these instructions for guaranteed success!

Part 1: Making the Zucchini Bar Batter

Preheat and Prep: First, preheat your oven to 350°F (175°C). Grease a 9×13-inch baking pan and set it aside.
Prepare the Zucchini: Wash your zucchini and grate it using the medium holes of a box grater. Gently blot the grated zucchini with paper towels to absorb some of the surface moisture, but do not squeeze it dry! You want to keep that moisture for the bars.
Mix the Wet Ingredients: In a large bowl, whisk together the eggs, granulated sugar, brown sugar, vegetable oil, and vanilla extract until smooth and well combined.
Combine Dry Ingredients: In a separate, medium-sized bowl, stir together the all-purpose flour, baking soda, salt, cinnamon, and nutmeg.
Create the Batter: Add the dry ingredients to the wet ingredients and mix until just combined. Be careful not to overmix. Finally, gently fold in the grated zucchini. If you’re using add-ins like chopped nuts or chocolate chips, fold them in now.

Part 2: Baking the Bars

Pour and Spread: Pour the batter into your prepared 9×13-inch pan and use a spatula to spread it evenly.
Bake to Perfection: Bake in the preheated oven for 25–30 minutes. The bars are done when a toothpick inserted into the center comes out clean and the edges are lightly browned.
Cool Down: Let the bars cool completely in the pan on a wire rack before you start the frosting.

Part 3: Whipping Up the Caramel Frosting

Melt Butter and Sugar: In a medium saucepan, melt the unsalted butter over medium heat. Add the packed brown sugar and stir continuously until the sugar has completely dissolved.
Bring to a Boil: Bring the mixture to a gentle, rolling boil and cook for exactly 1 minute, stirring constantly to prevent burning.
Add Milk and Cool: Remove the saucepan from the heat and carefully stir in the milk. The mixture will bubble up, so be cautious. Let it cool for a few minutes until it’s just warm, not hot.
Whisk in Sugar: Whisk in the powdered sugar and vanilla extract until the frosting is smooth and creamy.

Part 4: Frosting and Finishing

Spread the Frosting: Pour the warm caramel frosting over the completely cooled zucchini bars. Use an offset spatula to spread it evenly across the entire surface.
Let it Set: Allow the frosting to set for at least 30 minutes before slicing and serving. This will ensure clean cuts.

Tips for Success and Delicious Variations

Frosting Tip: For a thinner, glaze-like frosting, you can spread it over the bars while they are still slightly warm. For a thicker, fudgier frosting, wait until the bars are completely cool.
Add Some Crunch: Fold ½ cup of chopped walnuts or pecans into the batter for a wonderful texture and nutty flavor.
For Chocolate Lovers: Add ½ cup of mini chocolate chips to the batter for little pockets of melted chocolate.
Storage: Store the bars in an airtight container at room temperature for up to 3 days or in the refrigerator for up to a week. They are fantastic when served slightly chilled!

Zucchini Bars with Caramel Frosting

These ultra-moist zucchini bars are infused with warm spices and topped with rich, buttery caramel frosting. Perfect for potlucks, parties, or anytime you need a show-stopping dessert.

Print Recipe Pin Recipe

Prep Time 20

Cook Time 30

Total Time 1 20

Course Dessert, Snack

Cuisine American

Servings 20 bars

Ingredients

Zucchini Bars

2 cups grated zucchini do not peel; gently blotted but not squeezed dry
1 ½ cups all-purpose flour
1 tsp baking soda
½ tsp salt
1 ½ tsp ground cinnamon
¼ tsp ground nutmeg
½ cup granulated sugar
½ cup brown sugar packed
2 large eggs
½ cup vegetable oil
1 tsp vanilla extract

Caramel Frosting

½ cup unsalted butter
1 cup brown sugar packed
¼ cup milk whole milk or 2% preferred
2 cups powdered sugar
1 tsp vanilla extract
1 pinch salt optional, helps balance sweetness

Instructions

Preheat oven to 350°F (175°C). Grease a 9×13-inch baking pan.
In a large bowl, whisk together eggs, granulated sugar, brown sugar, oil, and vanilla until smooth.
In a separate bowl, mix together flour, baking soda, salt, cinnamon, and nutmeg.
Add the dry ingredients to the wet mixture and stir until just combined. Do not overmix.
Gently fold in the grated zucchini. Spread the batter evenly in the prepared baking pan.
Bake for 25–30 minutes or until a toothpick inserted into the center comes out clean. Cool completely in the pan on a wire rack.
To make the frosting, melt butter in a saucepan over medium heat. Add brown sugar and stir until dissolved.
Bring mixture to a gentle boil and cook for 1 minute, stirring constantly.
Remove from heat and carefully stir in the milk. Let cool for a few minutes until warm.
Whisk in powdered sugar, vanilla, and a pinch of salt (if using) until smooth.
Spread frosting over fully cooled bars. Let set for at least 30 minutes before slicing.

Notes

For extra flavor, fold in ½ cup chopped walnuts or chocolate chips to the batter. Store bars in an airtight container at room temperature for 3 days or in the refrigerator for 1 week.