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
yummmmm looks so good
Oh, and the doctored up cake mix recipe (the “easy white cake” you have on here) I have made into yellow cake and chocolate cake it it worked BEAUTIFULLY every single time. I even doubled it for yellow cake and then doubled it for chocolate cake then marbled half the yellow and half the chocolate in 2 sheet cake pans then (see previous comment) made the mousse and make the “perfect cupcake frosting and filling” x4 and frosted the whole cake with that. It was a HUGE sheet cake, probably would feed 60 people. And I got lots of “BEST birthday cake I’ve ever had!”. So… there you go.
I haven’t made this cake, but I made just the mousse this weekend, I doubled the recipe and it was the perfect amount to fill a sheet cake, just FYI!
This looks and sounds absolutely divine!
If you want just 1 tbsp boiling water, just fill your spoon from a boiling kettle!
I have been looking for a reason to make this cake.. I mean.. Me and my 3 yr old are the only ones in our house who would eat it. (hubby not a sweet loving guy). I thought.. maybe I will throw a party.. just so I can make it. But I don’t really have time. So, last night as I was laying in bed I decided I’m going to turn it into cupcakes. Will put the ganache on first and the use the mousse as kind of a frosting. Do you think that would work? I have never made mousse before. Then I can keep several for us, and give the rest to the neighbors hehe.
I’ve made this cake twice now and it got rave reviews. I make the chocolate cake in three layers, which allows me to use all the mousse and makes a stunning presentation. A tip – Spread the mousse on two of the cake layers, then refrigerate before putting them together to help the mousse set up firm. It also helps to refrigerate the ganache just a little to get the right consistency before pouring on the cake. Sometimes if you pour it right after you have melted the chips it can be a little too runny. Thanks so much for the recipe!!
Why couldn’t you just half each cake layer so that you have four thinner layers of cake then you could use all of the mousse by putting some between each layer? I’ve made a different mousse cake than this one before, and it had at least 3 or 4 layers.
Yep, you can totally do that if you want!
I want to like the screen right now!
Here's a question…I was thinking about pouring some evaporated milk on the cake after taking it from the oven to make it moist, but not so much that it would be soggy like a tres leches cake. What are you thoughts about that? Do you think it would be good?
FANTASTIC cake! Wishing I would have made two for book club last night so that I could have leftovers for breakfast this morning :).
To simplify the mousse step this time I made a small box of chocolate pudding with 1 1/2 C. milk and let that set for about five minutes in the fridge. I then whipped 1 C. whipping cream (sweetened with a touch of powdered sugar) and carefully folded in about half of my prepared pudding. Just as yummy as the original and less work.