Chocolate Peanut Butter Zucchini Brownies with Almond Flour

These chocolate peanut butter zucchini brownies with almond flour are fudgy, rich and secretly packed with vegetables. Finely grated zucchini melts into the batter and keeps every square moist, while creamy peanut butter, cocoa powder and almond flour give them a deep chocolate flavor and a tender, dense bite. A thick swirl of fluffy peanut butter frosting on top turns them into a bakery-style treat. The batter comes together in one bowl and bakes in a small loaf pan, so it is an easy snack or dessert any day of the week.

Why You’ll Like These Chocolate Peanut Butter Zucchini Brownies

They taste like a classic fudgy brownie, with a little extra goodness tucked inside.

• Moist and fudgy: the zucchini adds moisture without any vegetable taste.
• Made with almond flour: no wheat flour needed, which makes them naturally gluten-free.
• One bowl batter: simple stirring, no mixer required for the brownies.
• Chocolate and peanut butter: a favorite pairing in every bite, topped with creamy frosting.
• Great way to use zucchini: perfect when the garden or market gives you more than you can eat.

Ingredients for Chocolate Peanut Butter Zucchini Brownies

Brownies

• 1 large egg
• 1 cup packed finely grated zucchini, squeezed dry
• 1/2 cup creamy, runny peanut butter
• 1 tsp vanilla extract
• 1/4 cup maple syrup
• 1/2 cup packed brown sugar
• 2 tbsp unsweetened applesauce
• 1/2 cup unsweetened cocoa powder
• 1/2 cup almond flour
• 1/2 tsp baking soda
• 1/2 tsp salt

Peanut Butter Frosting

• 1/2 cup creamy peanut butter
• 3 tbsp unsalted butter, softened
• 1 cup powdered sugar
• 2 to 3 tbsp milk
• 1/2 tsp vanilla extract
• Pinch of salt

Ingredient Notes

Zucchini: Grate it on the small holes of a box grater so it disappears into the batter. Squeezing out the liquid is important, or the brownies will turn soggy and fall apart.

Peanut butter: A creamy, runny peanut butter mixes in smoothly. If yours is very thick, warm it for 10 to 15 seconds in the microwave and stir.

Almond flour: Use finely ground blanched almond flour for the softest texture. Almond meal with skins works but makes the brownies a little coarser.

Cocoa powder: Natural or Dutch-process unsweetened cocoa both work. Dutch-process gives a darker color and a smoother chocolate taste.

Applesauce: It adds moisture and gentle sweetness. Mashed ripe banana can replace it, but it will add a light banana flavor.

How to Make Chocolate Peanut Butter Zucchini Brownies

Make the Brownies

1. Prepare the pan. Preheat the oven to 350°F (175°C). Line a 9×5-inch loaf pan with parchment paper, leaving some hanging over the long sides so you can lift the brownies out later.
2. Squeeze the zucchini. Place the grated zucchini in a clean kitchen towel or several layers of paper towel and squeeze firmly over the sink until most of the liquid is gone. Pack it into a measuring cup to get 1 cup.
3. Mix the wet ingredients. In a large bowl, whisk the egg until frothy. Add the peanut butter, vanilla, maple syrup, brown sugar and applesauce and whisk until smooth. Stir in the zucchini.
4. Add the dry ingredients. Add the cocoa powder, almond flour, baking soda and salt. Stir with a spatula until no dry streaks remain. The batter will be very thick.
5. Bake. Spread the batter evenly in the pan and smooth the top. Bake for about 30 minutes, until the edges are set and a toothpick inserted in the center comes out with a few moist crumbs.
6. Cool and chill. Let the brownies cool in the pan for 15 minutes, then lift them out using the parchment. Let them cool completely on a wire rack, then chill for 30 minutes for clean, easy slicing.

Make the Frosting

1. Beat the base. Beat the peanut butter and softened butter together until creamy and smooth.
2. Add the sugar. Add the powdered sugar, vanilla, salt and 2 tablespoons of milk. Beat until fluffy, adding more milk a little at a time if needed for a spreadable texture.
3. Frost and slice. Spread the frosting over the cooled brownie slab in thick swirls, then cut into squares.

Tips for Perfect Zucchini Brownies

Squeeze Well

Wet zucchini is the most common reason these brownies turn gummy. Squeeze until only a few drops come out.

Do Not Overbake

Take them out when the center still has moist crumbs. They firm up as they cool and chill.

Frost Only When Cold

Warm brownies will melt the frosting. Make sure the slab is completely cool before spreading.

Clean Cuts

Use a sharp knife and wipe it with a warm, damp towel between cuts for neat squares.

Variations

• Chocolate chips: fold 1/3 cup chocolate chips into the batter for extra melty pockets.
• Nut-free: use sunflower seed butter instead of peanut butter in the batter and frosting.
• Chocolate drizzle: melt a little dark chocolate and drizzle it over the frosting.
• Crunchy topping: sprinkle chopped roasted peanuts over the frosting.
• Unfrosted: skip the frosting and dust the brownies with cocoa for a lighter snack.

Storage

Refrigerator: Because of the zucchini and frosting, store the brownies in an airtight container in the refrigerator for up to 5 days. Place parchment between layers.

Room temperature: They can sit out for a few hours for serving, but keep them chilled for longer storage.

Freezer: Freeze unfrosted squares, wrapped well, for up to 3 months. Thaw in the refrigerator overnight, then frost before serving.

Make ahead: The frosting keeps covered in the refrigerator for up to 1 week. Let it soften and beat again before using.

Frequently Asked Questions

Can you taste the zucchini in these brownies?

No. Finely grated zucchini blends into the chocolate batter and only adds moisture. Most people never guess it is there.

Can I use regular flour instead of almond flour?

You can replace the almond flour with about 1/3 cup all-purpose flour, but the brownies will be a little less tender and fudgy.

Can I bake them in a different pan?

An 8×8-inch pan works, but the brownies will be thinner. Start checking them after about 20 minutes.

Why are my brownies gummy in the middle?

The zucchini was not squeezed enough or the brownies were underbaked. Squeeze thoroughly and bake until the edges are set and the center has only moist crumbs.