Triple Chocolate Mousse Tart

This triple chocolate mousse tart is made with chocolate pate sablee crust, dark chocolate mousse, and white chocolate mousse. It’s the ultimate tart. It’s rich but subtle, sweet but lightly salty, and has the most amazing texture combination of smooth, silky, and soft but crunchy. This tart is so good that you will want to pass the recipe on for generations.

triple chocolate mousse tart

What is a Triple Chocolate Mousse Tart?

A triple chocolate mousse tart is a combination of a chocolate crust, dark chocolate mousse, and white chocolate mousse layered into one luxurious tart.

For the crust, we use a chocolate sable crust (similar to my chocolate sable cookies) that is formed into a 9.5 inch tart pan, and then baked to perfection. It’s a delicate crust with a beautiful chocolate flavor, and it’s just slightly salty to balance out the sweetness of the mousse.

The dark chocolate mousse is silky and rich, but the white chocolate mousse is light and balances out the flavor of the entire tart. This recipe was inspired by America’s Test Kitchen’s chocolate mousse cake.

triple chocolate mousse tart on a white background

What is the Best Chocolate for a Chocolate Tart?

When chocolate is the main feature of the dessert, don’t skimp on quality. There are times when it’s okay to use a generic brand of chocolate, but not for something where chocolate is the star.

I recommend a few brands below (that are affordable). If you really want to splurge, try something like Valrhona or Callebaut chocolate.

For the crust, use Dutch process cocoa powder.

Why?

Because Dutch process cocoa powder has a smoother flavor and is less acidic, which works best for the mousse.

For the dark chocolate mousse, use 56-60% bittersweet chocolate baking bar (Ghiradelli is the BEST chocolate for this recipe). You can find this chocolate at most grocery stores now too, so it doesn’t require a trip to a specialty store.

For the white chocolate mousse, use good-quality white chocolate chips. Either Ghiradelli or Guittard works well.

Why use white chocolate chips instead of baking chocolate for the mousse?

Because white chocolate is quite a bit runnier than regular chocolate (due to the lack of cocoa solids/nibs), so using white chocolate chips (which naturally have more structure) works better for this particular mousse.

triple chocolate mousse tart with a slice cut out

3 Foolproof Tips for Making a Triple Chocolate Mousse Tart

  1. Freeze the crust before baking. This helps the crust to hold its shape and shrink less during baking.
  2. Don’t overwhip the cream. Soft peaks barely hold their shape. We don’t want stiff peaks otherwise the texture of the chocolate mousse will be wrong and too stiff.
  3. Give the remaining white chocolate mousse 1-2 hours to chill before piping the border. This gives the mousse time to set up so it can hold its shape before piping the pretty border. Otherwise, it will run everywhere (not pretty).
slice of chocolate tart with chocolate mousse and white chocolate mousse

What Do I Need to Make This Tart?

  • A good 9-inch tart pan with a removable bottom is essential. Why do they even make tart pans without a removable bottom? It is so much easier to remove a tart from the pan to cut and serve it!
  • Pie weights help prevent the crust from shrinking during baking, so make sure you use pie weights or rice in the parchment liner.
  • An offset spatula to smooth out the layers of chocolate mousse.
  • A French star tip (see recipe)
  • A kitchen scale
Print

Triple Chocolate Mousse Tart

a slice of triple chocolate mousse tart on a speckled plate, showing the layers of the chocolate mousse

5 Stars 4 Stars 3 Stars 2 Stars 1 Star

No reviews

  • Author: Camille
  • Prep Time: 3 hours
  • Cook Time: 20 minutes
  • Total Time: 3 hours 20 minutes
  • Yield: 1 9-inch tart 1x
  • Category: tarts

Ingredients

Units Scale

Chocolate Pate Sablee

  • 113 g unsalted butter, room temp (65 F)
  • 50 g light brown sugar
  • 25 g Dutch process cocoa powder
  • 125 g all-purpose flour
  • 1/4 tsp kosher salt (Morton’s)
  • 1 large egg yolk
  • 9.5 inch tart pan

Dark Chocolate Mousse

  • 5 g cocoa powder(Dutch-processed)
  • 30 ml hot water
  • 85 g (3 oz) baking chocolate, 56-60% cocoa (I recommend this one)
  • 160 ml heavy cream
  • 15 g granulated sugar
  • Pinch salt

White Chocolate Mousse

  • 3/4 tsp gelatin
  • 1 Tbs cold water
  • 180 g white chocolate chips (pref. Ghiradelli)
  • 130 g heavy cream, to heat
  • 235 g heavy cream, chilled
  • Piping bag
  • French Star Tip (like this or this)

Instructions

For the Crust

  1. Cream butter on low speed in a stand mixer with a paddle attachment for 1 minute.
  2. Combine all dry ingredients, including the brown sugar. Add dry ingredients to the mixer on low in 3 additions, mixing between each addition until combined. It will look a bit crumbly still.
  3. Add the egg yolk and mix on medium low until the dough comes together. 
  4. On a floured surface**, roll the dough to a 12-inch circle (or until 1/8 inch thick) and transfer to a 9.5-inch tart pan. Note, this dough is fragile and tends to tear. If the dough tears, press it back together in the tart pan (the dough is very forgiving!). Use a knife to trim the edges of the tart along the edge. 
  5. Dock tart(prick with a fork), and freeze for at least 1 hour. 
  6. Preheat oven to 350 F/ 175 C and remove tart from freezer. Cut a piece of parchment paper slightly bigger than the tart, and spray with nonstick spray. Press the parchment (sprayed side down) into the tart shell, and add pie weights.
  7. Bake for 20 minutes, then remove the pie weights and parchment paper. Return the tart to the oven for another 5-8 minutes. The tart crust should not look moist anymore when done.

For the Chocolate Mousse

  1. Combine hot water and cocoa powder in a bowl, stir, and set aside. 
  2. Melt chocolate in a double boiler and remove from heat (or melt in microwave). Stir in hot water/cocoa powder and set aside.
  3. In a medium bowl, mix the heavy cream, sugar, and salt with a hand mixer and whisk attachment until soft peaks form. 
  4. Stir 1/4 of the whipped cream into the slightly warm chocolate, and then fold the remaining whipped cream into the mixture until no streaks show. The chocolate/cocoa should not be firm or stiff when adding the whipping cream. Warm the chocolate slightly if it hardens before adding the whipped cream.
  5. Pour mousse into the chocolate sablee tart shell and spread evenly with an offset spatula. Refrigerate for 20 minutes and prepare the top layer.

For the White Chocolate Mousse

  1. Pour water into a small bowl and sprinkle gelatin over the water. Let gelatin bloom for 5 minutes.
  2. Bring 130 ml of heavy cream to a boil and stir in gelatin.
  3. Roughly chop chocolate chips, and put them into a large bowl. 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 of whipped cream into the white chocolate and then fold the remaining whipped cream into the white chocolate.
  6. Pour white chocolate mousse into the tart (you’ll use between 1/2 – 3/4 of the chocolate mousse in the tart) and spread evenly. Pour the remaining white chocolate mousse into a piping bag fitted with a French star tip. Twist the ends so the mousse can’t drip. Place the tart and the white chocolate mousse in the fridge for 1.5 hours.
  7. Remove tart and white chocolate mouse from the fridge and pipe a star border on the outer edge of the tart. Return to fridge and chill for another 1-2 hours.
  8. Slice and enjoy. This tart should be covered in a container after it chills and sets, and it will stay fresh up to 1 week in the fridge.

Notes

This is a Baker Street Society recipe.

pin image for triple chocolate mousse tart

8 Comments

  1. Pingback: Chocolate Peanut Butter Mousse Tart - BakerStreetSociety

  2. Pingback: Chocolate Mousse (Mousse au Chocolat) - BakerStreetSociety

  3. Pingback: Molten Chocolate Lava Cakes - BakerStreetSociety

  4. Pingback: Baked Alaska Recipe - BakerStreetSociety

  5. Pingback: Lemon Christmas Cookies - Baker Street Society

  6. Pingback: Lemon Christmas Cookies | Baker Street Society

  7. Pingback: Mini Lemon Meringue Tartlets (Tartelettes Citron Meringue) - Baker Street Society

  8. Pingback: Small Fruit Tarts Recipe | Baker Street Society

Leave a Comment

Your email address will not be published. Required fields are marked *

Recipe rating 5 Stars 4 Stars 3 Stars 2 Stars 1 Star

*