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Best Ever Vegan Chocolate Mousse Cake

Easy Vegan Chocolate Mousse Cake (Gluten Free + Nut Free!)

  • Author: thebananadiaries
  • Prep Time: 20
  • Cook Time: 35
  • Total Time: 55 minutes
  • Yield: 16 1x
  • Category: Dessert
  • Method: Baking
  • Cuisine: American
  • Diet: Vegan


This decadent and rich vegan chocolate mousse cake is an absolute dream! With fudgy brownie cake layered with an unbelievably smooth and fluffy eggless and dairy free chocolate mousse, this chocolate mousse cake is a crowd pleaser, whether you’re vegan or not!



Vegan Brownie Cake Layer:

  • 1 cup (100 grams)  oat flour, sifted 
  • 1/4 cup (25 grams) cocoa powder 
  • 1/2 cup (90 grams) coconut sugar 
  • 2 tsp arrowroot powder
  • 1/2 cup (100 mL) unsweetened dairy free milk + 1 tsp acv, room temperature, mixed before the batter
  • 1/2 cup (150 grams) unsweetened applesauce, room temperature 
  • 3 tsp baking soda + 1 tsp apple cider vinegar (DON’T mix until you’re about to add to the batter)

Vegan Chocolate Mousse:

  • 1 cup (7 ounces) vegan dark chocolate
  • 1 cup (210 mL) aquafaba*
  • 1 tsp cream of tartar
  • 1/2 cup (90 grams) coconut sugar


  1. Please read through the instructions first before beginning, and measure out ingredients for the brownie cake layer. 
  2. Preheat the oven to 350F. Prepare an 8″ springform pan with 4″ walls by lining the bottom with parchment paper and greasing the edges of the springform pan with olive or cooking oil. Set aside. Prepare the vegan buttermilk by mixing together the dairy free milk and apple cider vinegar in a small bowl. Set aside to thicken. 
  3. Make the brownie cake batter: In a large bowl, whisk together the oat flour, cocoa powder, coconut sugar, and arrowroot powder. Set aside. In a medium bowl, whisk together the dairy free milk and acv mixture with the applesauce. Pour the wet mixture into the dry ingredients and whisk together until the dry ingredients have just combined with the wet. Then in a separate ramekin, mix the baking soda with the apple cider vinegar until it foams. Add immediately into the batter and mix together.
  4. Bake the brownie cake layer: Pour the batter into the springform pan and bake for 35 minutes, or until a toothpick comes out clean. Remove from the oven and allow the cake to cool in the springform pan for 30 minutes. Then transfer the cake in the springform pan still to the freezer to chill for 30 minutes. 
  5. Prepare the chocolate mousse: only after the brownie cake layer has chilled for 30 minutes in the freezer, prepare the chocolate mousse. 
  6. Melt the chocolate. In a microwave safe bowl or by tempering the chocolate over the stove, heat and stir the chocolate until melted. If using a microwave, use 30 second intervals, stirring in between each interval until the chocolate is about half way melted. Then stir the chocolate until melted, without heating it again. Set the chocolate aside to cool while you make the mousse.
  7. Prepare the vegan chocolate mousse. First start by adding the aquafaba, cream of tartar, and 2 tbsp from the coconut sugar into a stand mixer bowl with whisk attachment. Turn the stand mixer on to medium speed, mixing the aquafaba until it begins to foam. Once the mixture starts to foam, turn the speed up to high speed, and whip the aquafaba for 6-7 minutes, until soft peaks are achieved. Then add in the remaining coconut sugar. Turn the speed up to high speed again, and allow the mixture to mix for another 8-10 minutes, until medium peaks are achieved.
  8. Fold the chocolate into the mousse: once the peaks are achieved, pour the cooled chocolate into the mousse mixture. Use a rubber spatula to gently gold the chocolate into the mousse, using a “J” swoosh movement. Fold until the chocolate is evenly distributed throughout the mousse, being careful not to over mix the mousse and deflate it.
  9. Assemble the chocolate mousse cake: Pour the mousse on to the brownie cake layer, and use a rubber spatula to smooth the top. Place the mousse cake into the freezer to chill for 3 hours.
  10. Serve! Once the mousse cake is entirely set, use a butter knife to carefully run the edges of the mousse cake walls and sides of the springform pan to easily release the cake. Carefully release the springform cake walls and plate the mousse cake. Decorate with berries and server immediately. When not slicing, keep the mousse cake in the fridge or freezer. This is because at room temperate, aquafaba begins to soften quite quickly, so this cake shouldn’t be left out for more than 30 minutes. 
  11. Storage: store any leftovers in an airtight container in the freezer for up to 2 months.


Vegan chocolate: I recommend using Pascha Organics 100% or 85% dark chocolate here, either in bar form or chocolate chip form.

If not gluten-free: you can swap in 125 grams all-purpose flour for the oat flour. That’s about 1 cup, spoon and leveled. 

Store this chocolate mousse cake in the fridge or freezer when not serving.

Please read the full post for more details and tips!


  • Serving Size: 1 slice
  • Calories: 164
  • Sugar: 17.7 g
  • Sodium: 398.5 mg
  • Fat: 0.6 g
  • Saturated Fat: 0.5 g
  • Carbohydrates: 33.8 g
  • Fiber: 3 g
  • Protein: 3.1 g
  • Cholesterol: 0 mg

Keywords: vegan chocolate mousse cake, chocolate mousse cake, easy chocolate mousse cake