Peanut Butter Zucchini Cake

Peanut Butter Zucchini Cake – Moist, Nutty & Topped with a Peanut Butter Drizzle

This incredibly moist and flavorful cake is the perfect way to use up summer zucchini. The vegetable disappears into the batter, leaving behind a tender crumb and adding moisture without a vegetal taste. The rich peanut butter flavor is complemented by a sweet and salty peanut butter drizzle.

Prep Time: 20 minutes
Cook Time: 30-40 minutes
Cool Time: 1 hour
Total Time: About 2 hours
Yields: 12 servings

Ingredients

For the Cake:

1 cup (258 g) creamy peanut butter
1 cup (200 g) packed brown sugar
1 large egg, room temperature

1 teaspoon vanilla extract
¼ cup (61 g) buttermilk, room temperature
1½ cups (187.5 g) all-purpose flour

½ teaspoon kosher salt
½ teaspoon baking soda
1 cup zucchini, peeled, shredded, undrained (about 1 medium zucchini)

For the Peanut Butter Drizzle:

½ cup (65 g) powdered sugar, sifted

2 tablespoons creamy peanut butter
2-3 tablespoons milk (any kind)
¼ teaspoon vanilla extract

Pinch of salt

Instructions

1. Prepare the Oven and Pan:

Preheat your oven to 350°F (175°C).
Grease and flour an 8×8 inch or 9×9 inch square baking pan, or line it with parchment paper, leaving an overhang for easy removal.

2. Combine Wet Ingredients:

In a large bowl, using a hand mixer or a stand mixer fitted with the paddle attachment, beat the peanut butter and brown sugar together on medium speed until well combined and creamy.
Beat in the egg and vanilla extract until fully incorporated.

Mix in the buttermilk. The mixture may look a little grainy or separated at this point, which is normal.

3. Combine Dry Ingredients:

In a separate medium bowl, whisk together the flour, kosher salt, and baking soda.

4. Make the Batter:

Gradually add the dry ingredients to the wet ingredients, mixing on low speed just until no streaks of flour remain. Be careful not to overmix.
Using a spatula, fold in the shredded zucchini (with all its liquid) until it is evenly distributed throughout the batter.

5. Bake:

Pour the batter into the prepared pan and spread it into an even layer.
Bake for 30-40 minutes, or until a wooden skewer or toothpick inserted into the center of the cake comes out with just a few moist crumbs attached. The top will be golden brown and should spring back lightly when touched.

6. Cool:

Place the pan on a wire rack and allow the cake to cool completely in the pan. This is a crucial step for the cake to set properly before adding the drizzle.

7. Make the Peanut Butter Drizzle:

Once the cake is cool, make the glaze. In a small bowl, whisk together the sifted powdered sugar, 2 tablespoons of peanut butter, 2 tablespoons of milk, vanilla, and a pinch of salt.

Whisk until completely smooth. If the glaze is too thick to drizzle, add the remaining tablespoon of milk, a teaspoon at a time, until you reach your desired consistency.

8. Finish the Cake:

Drizzle the peanut butter glaze over the completely cooled cake.
Allow the glaze to set for about 15 minutes before slicing and serving.

Tips for Success:

Do Not Squeeze Zucchini: Using the zucchini undrained, with all its natural water, is the secret to the cake’s incredible moisture.

Room Temperature Ingredients: Using room temperature egg and buttermilk helps them incorporate more smoothly into the peanut butter, preventing the batter from seizing or curdling.
Avoid Overmixing: Mix the batter just until the ingredients are combined. Overmixing develops gluten, which can lead to a tough cake.
Cool Completely: This is a very moist cake. Cutting it while warm will result in messy crumbs. Letting it cool ensures clean slices.

Variations: For a extra crunch, fold ½ cup of chopped peanuts or chocolate chips into the batter before baking.