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–+ servings

Gluten-Free, Vegan Triple Chocolate Zucchini Sheet Cake

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Prep Time: 30 minutes
Cook Time: 35 minutes
Cooling time:: 1 hour
Total Time: 2 hours 5 minutes
Servings: 12

Equipment

  • 9x13" glass baking dish
  • Parchment paper
  • Small glass mixing bowl or measuring cup
  • Large mixing bowl
  • Silicone spatula
  • Hand mixer

Ingredients

  • 1 ¼ cup oat milk
  • 1 tbsp apple cider vinegar
  • 1 cup grated zucchini (measure when first grated, then squeeze out as much liquid as possible)
  • ½ cup vegan, soy-free, nut-free butter, such as Soy-Free Earth Balance, melted in the microwave and brought to room temperature
  • 1 ¾ cups sugar
  • ½ cup packed brown sugar
  • ¾ cup vegan, nut-free plain, unsweetened yogurt, such as Oatly
  • 3 cups gluten-free one-to-one baking flour (such as Bob's Red Mill)
  • 1 cup unsweetened cocoa powder
  • 2 tsp baking powder
  • 1 tsp baking soda
  • 1 cup hot coffee

For the Frosting:

  • ½ cup room temperature vegan, soy-free, nut-free butter, such as Soy-Free Earth Balance
  • ¼ cup room temperature vegan, nut-free sour cream
  • 1 cup vegan dark chocolate chips, such as Enjoy Life, plus more for topping
  • 1 tbsp coconut oil
  • 4-6 cups powdered sugar
  • ¼ cup cocoa powder
  • extra oat milk for thinning out the frosting if needed

Instructions

  • Preheat the oven to 350 degrees F.
  • Line the glass baking dish with parchment paper.
  • Make the vegan buttermilk: In a glass bowl, combine 1 1/4 cups oat milk and 1 tbsp apple cider vinegar and allow to sit at room temperature (mixture will curdle a bit and this is normal).
  • Grate zucchini and squeeze out as much liquid as possible.
  • In a large mixing bowl, whisk together melted vegan butter, sugar, brown sugar and vegan yogurt.
  • Add zucchini and stir until combined.
  • Sift in flour, cocoa powder, baking powder and baking soda (do not mix yet).
  • Add vegan buttermilk mixture and whisk. Before dry ingredients are fully incorporated, add hot coffee and fold batter with a silicone spatula or spoon until just incorporated - do not over mix (the batter will be a bit slippery and slimy; this is normal).
  • Pour the batter into the prepared baking dish and place in the oven for about 40 minutes or until a toothpick inserted into the center of the cake comes out clean.
  • Remove cake from oven and allow to cook completely for about 1 hour.
  • When you're ready to assemble the cake, remove the butter and sour cream from the refrigerator and allow to come to room temperature.
  • Make the frosting: Using a hand mixer, cream together ½ cup vegan butter until fluffy (about 3 minutes).
  • Add sour cream to butter and mix again.
  • Place the vegan chocolate chips and coconut oil into a small glass bowl and microwave in 30-second increments, stirring in between each time, until chocolate is melted and smooth. Allow it to come to room temperature.
  • Pour the chocolate mixture into the butter and sour cream mixture. Mix until smooth.
  • Add powdered sugar in 2-cup increments until a frosting consistency is reached, then add cocoa powder and mix until fluffy.
  • If frosting becomes too stiff, add a bit of oat milk in 1 tbsp increments.
  • Frost the cake, top with more vegan chocolate chips if desired, and serve!
  • Leftovers can be stored in an airtight container for up to 3 days.