Mousse in French literally means froth or foam. This melt-in-the-mouth mousse marries the classic flavours of chocolate and orange, is simple to prepare, and makes a magical finale to any meal.
Place the chocolate, butter and orange juice in a heatproof bowl over a pan of just-simmering water. When the chocolate and butter have melted, stir in the cocoa powder. Remove from the heat and whisk in the egg yolks and Cointreau. Leave to cool.
In a chilled bowl, beat the cream until soft peaks form. Cover and refrigerate until ready to use.