15 g semi-sweet or bitter-sweet chocolate
1/4 cup (2 fl oz / 60 ml) milk
1/4 cup (4 fl oz / 125 ml) heavy cream
1. Put the chocolate in a heatproof bowl. In a small saucepan over medium-high heat, bring the milk just to a boil. Remove from the heat and immediately pour over the chocolate. Stir with a wire whisk until the chocolate melts and the mixture is smooth.
2. In a clean bowl, using a balloon whisk, whop the cream just until soft peaks form.
3. Gently fold the cream into the chocolate just until the two mixtures are incorporated. Do not overfold, or the filling will be gritty. Cover with plastic wrap and refrigerate until firm and spreadable, about 1 hour, or for up to 3 days.
Please keep in mind these need to be refrigerated, as the frosting is mousse and can melt!