This Chocolate Mousse Crunch Cake is my all-time favorite special occasion cake. Not only does it wow people presentation-wise, but it’s pretty knock-your-socks-off tasty as well. As long as you like chocolate. Because if you’re a chocolate hater, this recipe isn’t for you. It’s got 2 layers of rich chocolate cake, sandwiched with decadent chocolate mousse, drizzled with ganache and sprinkled with chopped toffee bits. If you like, you can even top it with a cloud of whipped cream like I did in these photos.
Ingredients and Equipment Needed
This is just a preview of ingredients and method, keep scrolling for full printable recipe.
Cake
- Boxed devil’s food cake mix – I like Duncan Hines because their biggest by volume of ingredients, but any brand will work.
Filling and Topping
- Chocolate mousse
- unflavored gelatin
- water
- sugar
- vanilla
- cocoa powder
- vanilla extract
- Chocolate ganache
- semi-sweet or dark chocolate
- heavy whipping cream
- butter – optional
- Heath toffee bits – I’m using the ones that have some chocolate on them, but the plain ones also work. These are sold by the chocolate chips on the baking aisle. You could also crush up some Heath toffee bars if that’s all you can find.
- Sweetened whipped cream – Optional, but I like plopping some on top! If you need quantities, you can follow this recipe for sweetened whipped cream.
Helpful Equipment
- Straight sided cake pans – Our favorite cake pans to use are the kind with straight sides like these Straight-Sided 8-inch cake pans. They are great for any layer cake, but especially bare cakes like this where the sides are exposed.
How to Make Chocolate Crunch Cake
- First you’ll bake your cake layers according to the package directions.
- Next you’ll make a delicious chocolate mousse from whipped cream, cocoa powder, vanilla, and gelatin to stabilize it.
- You’ll also need to make a quick recipe of chocolate ganache from chocolate and heavy cream.
- To assemble the cake, trim off the domed top of each cake layer if necessary. Place one layer on a serving plate and spread chocolate mousse over the cake. Sprinkle Heath bits over the mousse and then place second layer of cake on top.
- Spoon ganache over the top layer, allowing it to drip down the sides. Sprinkle with additional Heath bits and refrigerate until ready to serve.
- If desired, top with sweetened whipped cream (and maybe some more Heath bits!) before serving.
Storing and Other Tips
- Because of the Heath bits, this cake should be served within 24 hours of assembly, ideally within several hours of assembly, as the Heath bits will soften over time.
- If you have leftovers, store them tightly wrapped in the refrigerator and enjoy within 3-4 days for best results.
- Note on Ganache: To get nice drips down the sides, avoid trying to actually spoon ganache down the side of your cake. Spread a nice even layer right on top. Then use a spoon to gently start spreading toward the edges. You just need to nudge a little and you’ll see the chocolate wave start moving toward the side and down the edge. Let gravity do the work! That way you get nice pretty drips without overdoing it.
Make Ahead Options
One of the great things about this easy chocolate cake recipe is that you can just use a boxed cake mix. I figure that there’s so much going on here that you don’t need to bother with a from-scratch chocolate cake, you know? And if you make the ganache ahead of time and just heat it up, and make the cake ahead of time, by a few hours or a day or even a few days (just wrap the layers in plastic wrap and freeze them), the rest comes together in no time.
Frequently Asked Questions
Can I make this gluten-free?
Absolutely, just use your favorite gluten-free chocolate cake recipe or mix!
Can I make this cake in a 9×13 pan?
Sure! I would bake the cake and then maybe poke a few holes with dowel or wooden spoon handle and spoon ganache over it while it’s still slightly warm, then cool and top with mousse and Heath bits!
How long can this cake be out of the refrigerator?
Because of the fresh dairy ingredients in the filling and topping, this cake should not be out of the refrigerator for more than 2 hours.
Can I make this into cupcakes?
I don’t see why not? I would dip the cupcakes in ganache and let it set, then top with the mousse and Heath bits. You could drizzle a little extra ganache over the tops as well!
Chocolate Mousse Crunch Cake
An easy chocolate mousse and toffee filling is sandwiched between moist layers of chocolate cake and finished off with rich, gooey ganache and more toffee bits.
Servings slices
Equipment
- 8-inch round cake pans
Ingredients
Cake
- 1 package Duncan Hines Devil’s Food Cake prepared as directed and baked in two 8-inch round pans
Ganache
- 8 ounces semi-sweet or dark chocolate by weight in ounces
- 8 ounces heavy whipping cream measured by weight in ounces like the chocolate, NOT fluid ounces
- 2 teaspoons butter optional, for a rich, glossy ganache
Chocolate Mousse
- 1 teaspoon unflavored gelatin
- 1 tablespoon cold water
- 2 tablespoons boiling water just heat it in a small bowl in your microwave
- ½ cup sugar
- 1/4 cup unsweetened cocoa powder
- 1 cup whipping cream
- 1 teaspoon vanilla
Additional Toppings
- 8 ounces Heath English toffee bits or crushed Heath bars
- Optional: extra sweetened whipped cream, for serving
Instructions
Bake Cakes
- Bake cake according to cake mix instructions in 2 8″ round pans. Allow to cool and set aside. This can be done several days in advance; just freeze the cakes when you’re done.
Make Chocolate Mousse
- In a small bowl, combine gelatin and cold water and allow to stand for about 1 minute. While gelatin is softening, bring about 1 cup of water to a boil in the microwave and measure out 2 tablespoons. Discard the rest. Whisk the 2 tablespoons of boiling water into the softened gelatin and allow to cool slightly.
- In a medium mixing bowl, combine sugar, cocoa powder, whipping cream, and vanilla. Beat with an electric mixer until medium-stiff peaks form. Mix in gelatin mixture and refrigerate for 30 minutes.
Make Ganache
- Be sure to measure your chocolate and heavy cream using the same units on a kitchen scale. For more information on this, see this Easy Chocolate Ganache recipe linked in the notes below.
- Place chocolate (and butter if desired) in a heat-safe bowl.
- Heat cream either in the microwave or on the stovetop, until small bubbles start to appear around the edges but not to boiling. Pour hot cream over chocolate and let sit undisturbed for 3-4 minutes.
- Whisk until smooth. Allow to cool slightly.
Assemble Cake
- With a serrated knife, carefully slice the dome-iest part of each cake layer off so the layers are level. Place one layer on the serving plate and spread chocolate mousse over the cake (see note below). Sprinkle with Heath bits.
- Place second layer on top of Heath bits.
- Spoon ganache over the top layer, allowing it to drip down the sides. Sprinkle with additional Heath bits and refrigerate until ready to serve. If desired, top with sweetened whipped cream (and additional Heath bits if desired) before serving.
Notes
- Because of the Heath bits, this cake should be served within 24 hours of assembly, ideally within several hours of assembly, as the Heath bits will soften over time.
- If you have leftovers, store them tightly wrapped in the refrigerator and enjoy within 3-4 days for best results.
- This recipe makes more mousse than you will probably need. Feel free to use as much or as little as you desire in the filling and snack on the rest! You could also spoon the extra on top instead of whipped cream.
Make Ahead Options
One of the great things about this easy chocolate cake recipe is that you can just use a boxed cake mix. I figure that there’s so much going on here that you don’t need to bother with a from-scratch chocolate cake, you know? And if you make the ganache ahead of time and just heat it up, and make the cake ahead of time, by a few hours or a day or even a few days (just wrap the layers in plastic wrap and freeze them), the rest comes together in no time.Nutrition
Calories: 544kcal, Carbohydrates: 57g, Protein: 6g, Fat: 35g, Saturated Fat: 18g, Polyunsaturated Fat: 3g, Monounsaturated Fat: 8g, Trans Fat: 0.03g, Cholesterol: 50mg, Sodium: 384mg, Potassium: 319mg, Fiber: 4g, Sugar: 39g, Vitamin A: 599IU, Vitamin C: 0.2mg, Calcium: 97mg, Iron: 4mg
Calories: 544kcal
Cost: $15
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Questions & Reviews
So…have you tried this in cupcake form yet? I think that I am going to give it a shot this weekend for a family get-together! Thanks for the brilliant cake idea!!!
Wow that looks amazing, and I don't even like cake.
Love everything you make. L. O. V. E. Would this cake do well sitting as a centerpiece during a dinner? Would I want to freeze partially, or just refridgerate in prep for that?
ooooooh Kate. That looks sooooooo amazing.
thanks! much better this time! My mousse is a little softer than I anticipated, but at least it's clump free!
Rachel, I had that problem last night, I left it too long and it was a rubber disk, but this morning I I mix it a bit with the cold water, only let it stand one minute, then mixed in the hot water, and maybe let it cool one minute or so, then added it to the already whipped cream and mixed again. worked better to do it at the end otherwise it cools to much.
Yay! I got it to work! Same whipping cream, so not sure what the problem was, but maybe it was my Bosch mixer? with the center post and the small amount of mousse I think it had a problem mixing it well at all, I tried a hand mixer last night too but it was probably to late. This morning I did it with a hand blender and it worked great! And so yummy! I am so excited, using it in the filling for my son's Monster b-day cake today and adding gummy worms to the mousse for the kids!
Thanks!!
I think this looks awesome, but when I made the mousse, the gelatin just clumped up in it instead of mixing in. What did I do??? I have to take it to dinner and don't have time to make it again, so I think I'll mix in some of the toffee with the mousse and hopefully no one will notice the gelatin?
Looks fabulous and I love to bake! Hubby does all the cooking and I'm in charge of the sweet stuff! I may have to make this very soon!! Yum!!
No it's whipping cream, I considered getting the "Heavy" whipping cream but decided on the regular like the recipe said. :o(
I will try it again this week with different whipping cream, do you think Heavy would work too.