Indulge in Dark Chocolate Raspberry Mousse Cake:

This Dark Chocolate Raspberry Mousse Cake is the kind of dessert that looks like it came from a fancy bakery display, but it’s totally doable at home. You get a fudgy chocolate base, a bright raspberry layer, and a silky dark chocolate mousse that melts on your tongue.

It’s rich but not heavy, sweet but balanced, and the berry-chocolate combo is basically a guaranteed win. Plan ahead for chill time, and you’ll be slicing into clean, glossy layers like a pro.

Why You’ll Love This

Between the deep cocoa flavor, the pop of tart raspberries, and that cloud-like mousse texture, this cake hits every note: dramatic, cozy, and totally celebration-worthy—without requiring complicated pastry skills.

Ingredients

For the chocolate base: 3/4 cup (90g) all-purpose flour
1/2 cup (50g) unsweetened cocoa powder (Dutch-process or natural)
3/4 cup (150g) granulated sugar
1/2 teaspoon baking powder
1/2 teaspoon fine salt
2 large eggs, room temperature
1/2 cup (120ml) whole milk
1/3 cup (80ml) neutral oil
1 teaspoon vanilla extract
1/2 cup (120ml) hot coffee or hot water (coffee boosts the chocolate flavor)
For the raspberry layer: 2 1/2 cups (300g) raspberries (fresh or frozen)
1/4 cup (50g) granulated sugar
1 tablespoon lemon juice
2 teaspoons powdered gelatin + 2 tablespoons cold water (to bloom)
For the dark chocolate mousse: 8 oz (225g) dark chocolate (60–70%), finely chopped
1 1/4 cups (300ml) heavy cream, divided
2 tablespoons powdered sugar (optional, for a slightly sweeter mousse)
1 teaspoon vanilla extract
1 teaspoon powdered gelatin + 1 tablespoon cold water (to bloom)
To finish (optional but cute): extra raspberries, chocolate curls, cocoa powder, or a pinch of flaky salt

How to Make It

Prep your pan. Line the bottom of a 9-inch springform pan with parchment. Lightly grease the sides. Preheat oven to 350°F (175°C).
Make the chocolate base batter. In a large bowl, whisk flour, cocoa, sugar, baking powder, and salt. Add eggs, milk, oil, and vanilla; whisk until smooth. Stream in hot coffee/water and whisk again (the batter will be thin).
Bake. Pour into the pan and bake 18–22 minutes, until a toothpick comes out with a few moist crumbs. Cool completely in the pan. Once cool, if the top domed, level it gently so your layers stack neatly.
Cook the raspberry layer. In a saucepan over medium heat, simmer raspberries, sugar, and lemon juice 5–7 minutes until juicy and slightly thick. Optional: strain to remove seeds for a smoother layer.
Set the raspberry layer. Bloom 2 teaspoons gelatin in cold water for 5 minutes. Stir into the warm raspberry mixture until fully dissolved. Cool 10 minutes, then pour over the cooled chocolate base. Chill 45–60 minutes, until just set (it should jiggle slightly, not slosh).
Melt chocolate for mousse. Place chopped dark chocolate in a heatproof bowl. Warm 1/2 cup (120ml) of the heavy cream until steaming (not boiling), pour over chocolate, sit 1 minute, then stir until glossy. Let it cool to lukewarm.
Add gelatin for stability. Bloom 1 teaspoon gelatin in cold water for 5 minutes. Microwave 10–15 seconds until liquid, then whisk into the lukewarm chocolate mixture.
Whip the cream. Whip remaining 3/4 cup (180ml) heavy cream with powdered sugar (if using) and vanilla to soft-medium peaks. It should be fluffy and smooth, not stiff.
Fold and assemble. Fold whipped cream into the chocolate in 2–3 additions until no streaks remain. Spoon mousse over the raspberry layer and smooth the top.
Chill to set. Refrigerate at least 6 hours (overnight is even better) until fully set and sliceable.
Unmold and decorate. Run a warm knife around the edge, release the springform, and top with raspberries, chocolate curls, or a light dusting of cocoa.

Tips for the Best Results

Cool your base completely before adding raspberry, or the layer can melt and soak in.
Lukewarm chocolate is the sweet spot. If it’s hot, it melts the whipped cream; if it’s cold, it can seize into flecks.
Bloom gelatin properly. Give it the full 5 minutes so it hydrates, then fully dissolve it—no granules.
Soft-medium peaks = smooth mousse. Overwhipped cream can make the mousse grainy and harder to fold.
Chill time is non-negotiable. You need those hours for clean slices and that mousse-cake vibe.
For extra sharp layers, chill the raspberry layer until it’s set enough to support mousse without mixing.

Variations

Brownie base: Swap the cake layer for your favorite thin brownie recipe for a denser, fudgier bite.
White chocolate raspberry: Use white chocolate mousse and keep the raspberry layer the same for a brighter, sweeter twist.
Mixed berry layer: Replace half the raspberries with blackberries or strawberries (add a little extra lemon to keep it punchy).
Mocha moment: Add 1 teaspoon espresso powder to the mousse for a deep, coffee-chocolate finish.
Mini cakes: Build in jars or ramekins for cute single-serve desserts—just reduce chill time slightly.

Storage & Serving

Store the cake covered in the refrigerator for up to 4 days. For the cleanest slices, cut straight from the fridge with a warm, wiped-dry knife. Serve chilled for that mousse-firm texture, or let slices sit 10 minutes for a softer, meltier bite.

FAQ

How long does this mousse cake need to chill before slicing?

Plan for at least 6 hours, but overnight is best. The raspberry layer and mousse both need time to fully set so you get distinct layers and neat, bakery-style slices.

Can I use frozen raspberries?

Yes—frozen raspberries work perfectly. Simmer them straight from frozen; you may need an extra minute or two to thicken because they release more liquid.

Why did my mousse turn grainy or have tiny chocolate bits?

This usually happens when the chocolate mixture is too cool when you fold in whipped cream (it starts to set on contact), or when the cream is overwhipped. Aim for lukewarm chocolate and soft-medium peaks for the smoothest mousse.

Can I make this without gelatin?

You can, but the layers will be softer and more prone to slumping, especially at room temp. If you want to skip gelatin, keep the cake very cold and consider using a thicker raspberry compote (reduce it more on the stove) and a slightly firmer whipped mousse.

What’s the best dark chocolate to use for this recipe?

Choose a bar you’d actually enjoy eating—60–70% cacao is ideal for a balanced, rich flavor that doesn’t overpower the raspberry. Chocolate chips can work, but bars melt smoother and give a silkier mousse.