Chocolate espresso petit gateau is a dessert that never fails to impress. With an espresso mousse, chocolate cake truffle center, graham cracker crust, and a shiny chocolate mirror glaze, it always looks elegant and gourmet. The combination of chocolate and espresso in this dessert make it shine.
When you make petit gateaux, you need silicone molds. There is absolutely no way around it. I found mine at a thrift store, but there are many options online too. These molds are very similar to the ones that I have. (this is not an affiliate link.) The good thing is that molds are not very expensive and can be used time after time for years and years to come.
Petit Gateau – What it is and where it comes from
The first question that you are probably asking is, what is a petit gateau? Petit gateau is french for little cake, and traditionally this cake is made from mousse. These desserts can range from gourmet to extremely gourmet as pastry chefs have attempted to make this dessert more and more complex. The plural name for petit gateau is petit gateaux.
Typically a petit gateau has a mousse filling, a crust or cake base, a filling of some sort and a mirror glaze. In some cases the filling, mirror glaze, or the cake base is not used.
This petit gateau recipe has 4 main elements, the biscuit base, espresso mousse, chocolate cake truffle, and a shiny chocolate mirror glaze.
The Biscuit Base
This biscuit base is super easy to make! While some people go for all homemade elements, I decided to make a graham cracker crust biscuit to save just a little bit of time. All you have to do is mix all of the ingredients together, shape the biscuits, and then bake for 7-8 minutes!
The Espresso Mousse
I wanted to make a dessert that tasted like espresso, but not too much. I didn’t want the coffee flavor to be overpowering. This mousse has the perfect balance of flavor. Also this mousse is so simple compared to a traditional mousse. In most cases a mousse is made with custard and raw egg whites this one is not. Because this mousse is made with whipped cream, it is much lighter. It also only takes 10 minutes to make!
Also, keep in mind that the mousse needs to be completely frozen before you pour the glaze over the top. If the mousse is not frozen, then it will melt as you pour on the glaze.
Chocolate Cake Truffle Center
These petit gateaux have a very unique filling. When you compare these petit gateaux to others this filling stands out. While some opt for jam, caramel, or another flavored mousse, few opt for a cake truffle filling.
For this truffle filling, you are going to need a 9×9 pan of chocolate cake. If you want to use a boxed cake mix and save the rest of the cake for something else, be my guest. Otherwise, I have a recipe below that you can use instead!
Do not be afraid of mirror glaze. While it can seem intimidating, it is really not that hard. All you have to do is combine the ingredients in a saucepan, and heat them all together. When you pour the glaze on to the gateaux, you want to make sure that the glaze is in between 85-90 degrees Fahrenheit. If it is too warm it will slide off of the mousse. If it is too cold it will be gloppy and not pour on smoothly.
When you make these Chocolate Espresso Petit Gateaux, tag me on on Instagram! I love seeing what you are making! Also if you are on Pinterest don’t forget to save this recipe so that you can find it again later.
Chocolate Espresso Petit Gateau
Graham Cracker Crust Biscuit
- 2 cups Graham Cracker Crumbs
- ½ cup Flour
- 3 tbsp Brown Sugar
- 10 tbsp Melted Butter
- ½ tsp Pure Vanilla Extract
- 2½ cups Heavy Whipping Cream
- 2oz Espresso (Cooled to Room Temperature)
- ⅔ cup Powdered Sugar
- 2 tbsp Powdered Milk
- 1 tsp Vanilla Bean Paste or Pure Vanilla Extract
Chocolate Cake Truffle
- 1 9×9 Chocolate Cake
- 1 cup Espresso Mousse
- 1 tsp Espresso Powder
Chocolate Mirror Glaze
- 5 tsp Gelatin Powder
- ⅔ cup Corn Syrup
- 1 cup Water
- 1 cup Heavy Whipping Cream
- 1 cup Unsweetened Cocoa Powder
- Combine all of the ingredients for the graham cracker crust biscuit in a bowl. Mix until a crumble forms.
- Line a pan with parchment paper and press the biscuit onto the parchment. Form 12 tightly packed three-inch circles. Bake the biscuit at 350 for 7-9 minutes or until golden brown.
- Whip the cream until soft peaks form. Add all of the remaining ingredients and mix until fully combined and thick. Set aside in the refrigerator.
Chocolate Cake Truffle Filling
- Mash the 9×9 inch cake in a medium sized bowl. Add one cup of the mousse and one teaspoon of espresso powder. Mix until a smooth thick paste forms. Spread the mixture onto a sheet lined with parchment paper and freeze for 1-2 hours or until frozen. Remember to spread the mixture thin enough that you can cut twelve 1½ inch circles out of it.
- Once the filling is frozen, cut 12 1½ inch circles out of it.
- Grab the mousse out of the refrigerator and place in a piping bag. Fill each of the twelve silicone molds ⅔ full with the mousse. Add a disk of the chocolate cake truffle filling to each gateau. Pipe on more mousse and level off each silicone mold as needed.
- Freeze the mousses until completely frozen.
- Combine the gelatin with 2 tbsp of room temperature water.
- In a saucepan combine the corn syrup, water, cocoa powder, and heavy whipping cream. Heat until it is just starting to come to a boil. Stir in the gelatin until completely dissolved.
- Allow the mirror glaze to cool slowly on the counter until it reaches 85 degrees.
- Pull the mousses out of the freezer, unmold them and then place them on to a graham cracker biscuit. Place the assembled petit gateaux on a wire cooling rack. Pour the glaze over the tops of the petit gateaux and let them set. (This should take about 5 minutes.) Remove the petit gateaux from the cooling rack with a warm offset spatula.
- Garnish with chocolate dipped espresso beans if desired. The petit gateaux will keep in the refrigerator for up to 2 days.