This chocolate mousse filling for cakes is a light, whipped filling made from 4 main ingredients: 200 g (7 oz) of melted semi sweet chocolate, 1 cup of cold heavy cream, 2 tablespoons of powdered sugar, and vanilla. It takes about 20 minutes to make, chills for up to an hour, and fills a three layer 8 inch cake or 24 cupcakes.
It needs no gelatin or cornstarch. The cocoa butter in real chocolate firms the mousse as it chills, so it holds between layers and pipes like frosting. Two things decide whether it works: cream whipped only to soft peaks, and chocolate cooled until it is no longer warm but still pourable.
Following a special diet?
Every recipe on this site can be converted to gluten-free, vegan, dairy-free, keto, nut-free or egg-free with adjusted ratios so nothing falls flat.
Try the Recipe Converter →Quick Look
- Fills: one three layer 8 inch cake or 24 cupcakes
- Chocolate: 200 g semi sweet, 55% to 65% cocoa, chopped
- Cream: 1 cup (240 ml) cold heavy whipping cream, whipped to soft peaks
- Set: no gelatin; chill 30 to 60 minutes before layering
- Stiffer for piping: use 200 ml cream instead of 240 ml
- Keeps: up to 2 days in the fridge; best the same day; do not freeze
Can You Use Chocolate Mousse as Frosting?
Yes, this one is made for it. Because it is built on melted chocolate rather than cocoa powder, it chills to a thick, fluffy texture that spreads over the outside of a cake and pipes swirls on cupcakes. Think of it as a chocolate mousse frosting that tastes like ganache with air whipped into it.
For frosting, use 200 ml of cream instead of the full cup so it is a little stiffer, and chill it for 30 to 45 minutes before piping. Frost a chilled cake, and keep the finished cake in the fridge. Mousse frosting is softer than buttercream, so it is not the right choice for a cake that will sit in a warm room or outdoors for hours. For that, a whipped chocolate frosting or chocolate ganache frosting holds up better.
Choosing the Chocolate
The chocolate is the backbone of this mousse, so use one you enjoy eating straight. I use semi sweet between 55% and 65% cocoa. Much darker chocolate stiffens too much once chilled, and lower percentages taste flat. Chop it into small, even pieces so it melts gently over a double boiler, or in the microwave in 20 second bursts, stirring between each.
For a sweeter, milder mousse, use 100 g of milk chocolate and 100 g of semi sweet. Milk chocolate sets softer, so give it the full chilling time.
Whipping the Cream
Heavy whipping cream is essential. Lower fat creams will not whip or hold structure. Keep it cold straight from the fridge and whip it in a chilled bowl, a metal one if you have it, with the powdered sugar and vanilla. I have tried room temperature cream and it never sets the same.
Stop at soft peaks, when the cream holds its shape but the tips droop. Overwhipped cream is the most common cause of a grainy mousse, and it also makes folding harder.
Folding It Together
Let the melted chocolate cool until it is no longer warm to the touch but still fluid. Too hot and it melts the cream and the mousse turns runny. Too cool and it sets into hard flecks when the cold cream goes in. Stir one spoonful of whipped cream into the chocolate to loosen it, then fold in the rest in 2 or 3 additions with a rubber spatula.
Work gently and keep folding until no streaks remain. The finished mousse should be an even, light chocolate brown and hold soft peaks on a spoon. If you are unsure, spoon a little into a cup and chill it for 10 minutes. If it sets and scoops smoothly, you are ready.
Layering a Chocolate Mousse Cake
For clean slices, chill the mousse for about 45 minutes, until it spreads without sinking. Spread it between cooled layers, or pipe a ring of firmer frosting around each layer first if the cake is tall. Chill the assembled cake before slicing. My chocolate mousse cake and triple chocolate mousse cake show the full build.
It pairs well with a sour cream chocolate cake and fresh raspberries, or with a thin layer of raspberry cake filling. For a richer, denser layer, combine it with a ganache chocolate cake filling. If you want a different flavor in the same style, try vanilla mousse cake filling or peanut butter mousse filling.
Grainy, Runny, or Flat? Here Is Why
- Grainy: the cream was overwhipped or the chocolate was too hot. Start again with fresh cream and let the chocolate cool longer.
- Hard chocolate flecks: the chocolate was too cool when the cream went in.
- Too soft to layer: chill it longer, or fold in a little more softly whipped cream.
- Flat flavor: the chocolate was too low in cocoa. Use at least 55%, or add a little more vanilla or the pinch of salt.
Variations
Add 2 tablespoons of espresso for a mocha version, or see my mocha mousse. Fold 1 tablespoon of sour cream into the whipped cream for a gentle tang. It is also lovely spooned into glasses as a no bake dessert, layered into a trifle with chocolate sponge, spread into a tart shell, or swirled over chocolate mousse brownies. For a classic spoon dessert, my chocolate mousse recipe is softer and silkier.
How Long It Keeps
Store the mousse covered in the fridge for up to 2 days. After that it loses smoothness and flavor. For layer cakes I always use it the same day I make it. Do not freeze it, because the texture turns uneven when it thaws.
Mousse Filling Questions
Will chocolate mousse hold up between cake layers?
Yes, once chilled for 30 to 60 minutes. Keep the filled cake refrigerated until serving.
Do I need gelatin for chocolate mousse cake filling?
No. The cocoa butter in the melted chocolate sets the mousse as it chills.
Can you pipe chocolate mousse?
Yes. Use 200 ml cream for a stiffer mousse and chill it for 30 to 45 minutes before piping.
Can I make it ahead?
Up to 2 days in the fridge, though it is best used the same day.
Why is my mousse grainy?
The cream was whipped past soft peaks, or the chocolate was too hot when the cream was added.
Pin this chocolate mousse filling so you always have a reliable cake filling and frosting on hand. Tell me in the comments how you used it, or which variation you tried.
Chocolate Mousse Filling for Cakes
This chocolate mousse filling for cakes is a light, whipped chocolate mousse made with melted semi sweet chocolate, cold heavy cream, powdered sugar, and vanilla. It takes about 20 minutes plus chilling and fills a three layer 8 inch cake or 24 cupcakes with a fluffy, creamy layer. The cream is whipped to soft peaks and folded into cooled melted chocolate, and the cocoa butter sets it without gelatin. Use it as chocolate mousse cake filling, a chocolate mousse frosting for cakes and cupcakes, or in trifles, tarts, and mousse cups. Use 200 ml cream for a stiffer mousse to pipe. It keeps 2 days in the fridge; do not freeze.
Ingredients
- 200g (7 oz) semi-sweet chocolate (55–65% cocoa), chopped
- 1 cup (240ml) heavy whipping cream, cold
- 2 tablespoons powdered sugar (adjust to taste)
- 1 teaspoon pure vanilla extract
- Pinch of salt (optional, only if using unsalted chocolate)
Instructions
- MELT THE CHOCOLATE: Place the chopped chocolate in a heatproof bowl and melt gently over a double boiler, stirring until smooth. Alternatively, microwave in 20-second intervals, stirring between bursts until fully melted. Set aside and allow to cool to room temperature. The chocolate must not be warm when combined with cream to prevent seizing.
- WHIP THE CREAM: In a large chilled bowl, whip the cold heavy cream with powdered sugar and vanilla using a hand mixer or stand mixer fitted with the whisk attachment. Continue whipping until soft peaks form. The cream should hold its shape but remain smooth and slightly droopy. Avoid overwhipping, which can cause the mousse to become grainy.
- COMBINE CHOCOLATE AND CREAM: Once the chocolate has cooled to room temperature but remains pourable, add one spoonful of whipped cream to the chocolate and stir gently to loosen the texture. Then fold in the remaining whipped cream in 2 to 3 additions using a rubber spatula, mixing carefully to maintain volume. Fold until the mousse is smooth and evenly colored, with no visible streaks remaining.
Notes
For a firmer texture suitable for clean slicing, chill the mousse for 30 to 60 minutes before using it in cakes or tarts. Let the melted chocolate cool until no longer warm but still pourable, and whip the cream only to soft peaks to avoid a grainy mousse. For a stiffer mousse to pipe as frosting, use 200 ml cream instead of 240 ml. Use high quality chocolate, as it is the dominant flavor. Best used the same day but can be refrigerated for up to 2 days. Do not freeze.
Nutrition Information
Yield
24Serving Size
1Amount Per Serving Calories 86Total Fat 6.2gSaturated Fat 4.0gUnsaturated Fat 2.2gCholesterol 14mgSodium 9.3mgCarbohydrates 6.4gFiber 0.3gSugar 5.8gProtein 1.0g
