1 cup or 8 oz. good quality dark chocolate chips (180g)
1/2 cup warm water (120ml)
1/2 cup unsweetened cocoa powder (40g)
2 cups heavy cream or heavy whipping cream, cold (465ml)
1/4 cup powdered sugar (30g)
2 tsp vanilla extract (8ml)
pinch of fine salt (less than 1/8 tsp)
Electric hand mixer or stand mixer
Chocolate Mousse Cake Filling
Melt the chocolate chips by placing them in a medium-sized, heat-proof bowl. Heat in 20-30 second increments in the microwave, stirring after each increment until the chocolate completely melted and smooth. If you don’t have a microwave you can also use a double boiler.
In a small bowl, whisk together the warm water and cocoa powder. Pour into the melted chocolate and whisk together until smooth. The mixture should be somewhat thick. Set aside.
Add the heavy cream, powdered sugar, vanilla extract, and a pinch of fine salt in a large bowl or the bowl of a stand mixer fit with a whisk attachment.
Mix on medium-high speed until the whipped cream starts to gather in the whisk attachment and you can see texture around the edges of the bowl. The whipped cream should be thick and able to keep its shape. This usually takes about 2 1/2 to 3 minutes in my stand mixer.
Gently fold the chocolate mixture into the whipped cream using a rubber spatula. Use the spatula to swoop around the sides of the bowl and pull through the center like I show in the video of this recipe. Be careful not to over-mix the mousse, or it will become deflated and lose its structure.
Cover the mousse with plastic wrap and chill in the refrigerator for at least 2 hours or up to 2 days.