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Boston Mousse Cake

Boston Mousse Cake

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Prep Time 4 hours
Cook Time 30 minutes
Total Time 4 hours 30 minutes
Servings 15

Ingredients
  

For the Custard:

  • 2¼ cup Plant Milk 533ml
  • ¾ cup Granulated Sugar 150g
  • 5 Tbs Cornstarch 40g
  • ¼ teaspoon Turmeric
  • 1½ Tbs Vegan Butter 21g
  • 1 teaspoon Vanilla Extract 5ml

For the Chocolate Mousse:

  • 8 ounces Semi Sweet Vegan Chocolate 226g
  • 2 Tbs Hot brewed coffee 30ml
  • 1 teaspoon Vanilla Extract 5ml
  • ¼ cup Aquafaba 60ml
  • 4 Tbs Granulated Sugar 50g
  • ¼ teaspoon Cream Of Tartar
  • 1½ cups Vegan Whipped Cream

for the icing

Instructions
 

  • First prepare the chocolate cake recipe as per the instructions on that recipe post & divide the batter into 2-7" cake pans that have been greased & parchment lined.
  • Bake in a preheated 350°F oven for approximately 20 minutes or when they are springy to the touch when you gently press the centers
  • Cool the cakes in the pans then flip them out onto a cooling rack to cool the rest of the way.
  • Wash & re-grease & re-parchment line the pans, but this time you need 3-7" cake pans
  • Prepare the yellow cake recipe as per the instructions on that recipe post & divide the batter evenly between your prepared pans
  • Bake in a preheated 350°F oven for approximately 20 minutes or when they are springy to the touch when you gently press the centers
  • Cool the cakes in the pans and then flip them out onto a cooling rack to cool the rest of the way.
  • Next prepare the chocolate buttercream according to the instructions on that recipe post
  • Next prepare the custard: combine all the ingredients except for the vanilla extract& the vegan butter in a medium sauce pot over & cook over medium to high heat bringing to a boil stirring constantly to avoid scorching the bottom .
  • Once it starts to bubble let it boil on low heat for about 5 seconds.
  • Remove from the heat & add the vegan butter & vanilla extract stir until melted & smooth, reserve aside while you prepare the chocolate mousse recipe
  • For the chocolate mousse Melt the chocolate in a large bowl over a double boiler or in a microwave safe bowl
  • Combine the hot coffee & sugar in a small sauce pot and bring it to a rolling boil to dissolve the sugar
  • Next prepare your favorite vegan whipped cream *You will need 1½ cups total fully whipped cream
  • Add the hot brewed coffee & then the vanilla extract to the melted chocolate all at once while whisking vigorously to incorporate well.
  • Cool the chocolate mixture to about 80°F or tepid to the touch before folding in the whipped cream or it will melt back to liquid!
  • Add the reserved whipped cream & whisk smooth
  • Whip the aquafaba with the cream of tartar to stiff glossy peaks
  • Take a small portion of the AF meringue & fold into the chocolate mixture to lighten. Then fold in the rest of the AF gently
  • Set up your first cake layer in a cake ring mold lined with acetate cake strips *see video tutorial
  • Then build the cake inside the ring mold with a chocolate buttercream border to hold everything in alternating the cake layers as shown in the video tutorial

Video

Notes

Be sure to read all the notes for success above the recipe section 
Storage Boston Mousse cake must be kept refrigerated. This cake will stay fresh in the refrigerator for up to 7 days. I do not like to freeze custard filled cakes as they tend to get watery & separate on the thaw.
Tried this recipe?Let us know how it was!