1. Break the chocolate into small pieces and place it in a heatproof bowl over a pot of simmering water. Stir occasionally until melted and smooth. Remove from heat and let cool slightly.

2. In a chilled bowl, whip 3/4 cup of heavy cream to medium peaks. Place it in the fridge while you prepare the rest.

3. In a separate bowl, whisk the egg yolks with peppermint and vanilla extract. Slowly mix in the cooled melted chocolate until fully combined.

4. In a clean bowl, beat the egg whites with an electric mixer until soft peaks form. Gradually add sugar and beat until stiff peaks form.

5. Fold the whipped cream into the chocolate mixture in two additions. Then gently fold in the whipped egg whites until just combined.

6. Spoon the mousse into serving glasses. Cover and chill for at least 2 hours until set.

7. Before serving, top with whipped cream, crushed peppermint, and fresh mint if desired.