Triple Chocolate Mousse Tart

triple chocolate mousse tart slices



Tart Crust

  • 5 Tbs unsalted butter, softened
  • 1/4 cup light brown sugar
  • 1/2 tsp vanilla
  • 2 ounces semi-sweet chocolate bar or 60% dark chocolate bar, chopped into small pieces
  • 1/2 cup all-purpose flour
  • 1 Tbs unsweetened cocoa powder (1 oz)
  • 1/2 tsp Fleur de Sel or flaked sea salt

Middle Layer

  • 3 tsp cocoa powder(Dutch-processed)
  • 2.5 Tbs water
  • 3 oz. baking chocolate bar, 60% cocoa(bittersweet)
  • 2/3 cup heavy cream
  • 2 tsp sugar
  • pinch salt

Top Layer

  • 1/4 + 1/8 tsp gelatin
  • 1/2 Tbs cold water
  • 3 ounces white chocolate chips
  • 3/4 cup heavy cream
  • 1/2 tsp sugar


For the Crust

  1. Preheat oven to 350 degrees. Cream butter, brown sugar, and vanilla until smooth.
  2. Chop chocolate into thin slices, almost like shaved chocolate pieces.
  3. Add all dry ingredients to the mixer and mix just until combined.
  4. Pour dough into a 9-inch tart pan and press dough evenly into pan with the back of a measuring cup. Be sure to press dough firmly against the sides and trim off excess dough. If the crust is thin enough, you should have removed enough chocolate cookie dough to make 2 or 3 cookies afterward.
  5. Dock tart(prick with a fork), line with nonstick foil, and fill with baking weights. Refrigerate for 30 minutes, and then bake for 15 minutes.
  6. After 15 minutes, remove tart from oven, carefully remove foil, and bake for 5 more minutes. 
  7. Remove tart from oven and let cool completely, about 45 minutes.

For the Middle Layer

  1. Combine hot water and cocoa powder in a bowl and set aside. 
  2. Melt chocolate in a double boiler and remove from heat. Stir in hot water/cocoa powder and set aside.
  3. In a stand mixer or with a hand mixer, mix heavy cream, sugar, and salt until soft peaks form. 
  4. Stir 1/4 of the whipped cream into the chocolate, and then fold the remaining whipped cream in until no streaks show.
  5. Pour mousse into tart shell and spread evenly with an offset spatula. Refrigerate for 20 minutes and prepare top layer.

For the Top Layer

  1. Pour water into a small bowl and sprinkle gelatin over the water. Let gelatin bloom for 5 minutes.
  2. Bring 1/4 cup of heavy cream to a boil and stir in gelatin.
  3. Put chocolate chips into a bowl and pour heavy cream mixture over the chocolate chips. Stir until melted. Let cool for 8-10 minutes, stirring occasionally.
  4. Whip the remaining heavy cream and sugar until soft peaks form. 
  5. Stir 1/4 cup of whipped cream into chocolate and then fold the remaining whipped cream into the white chocolate.
  6. Pour white chocolate mousse into the tart and spread evenly. Refrigerate for at least 2 hours and enjoy. Keep leftover tart slices refrigerated.
  7. If desired, double the white chocolate mousse recipe to make a white chocolate star border as shown in the pictures. Otherwise, top with shaved chocolate or cocoa powder.


This is a Baker Street Society recipe.

Keywords: triple chocolate mousse tart, chocolate mousse tart, chocolate tart, triple chocolate mousse cake