Chill 1 1/2 cups whipping cream in refrigerator. Chill metal mixing bowl and mixer beaters in freezer.
On top of a double boiler, combine chocolate chips, vodka, Irish cream and butter. Melt over barely simmering water, stirring constantly. Remove from heat while a couple of chunks are still visible. Cool, stirring occasionally to just above body temperature.
Pour remaining 1/4 cup whipping cream into a microwave safe cup and sprinkle in the gelatin. Allow gelatin to “bloom” for 10 minutes (the gelatin will cause the cream to gel). Then carefully heat by microwaving the cream in 7 second intervals swirling after each interval until the cream is liquid again and most of the gelatin is dissolved. Do not boil or gelatin will be damaged. While stirring, strain the mixture into the cooled chocolate and set aside.
In the chilled mixing bowl, beat cream to medium peaks with sugar and vanilla. Stir 1/4 of the whipped cream into the chocolate mixture to lighten it. Fold in the remaining whipped cream in two doses. There may be streaks of whipped cream in the chocolate and that is fine. Do not over work the mousse.
Spoon into bowls or martini glasses and chill for at least 1 hour. Garnish with almonds/fruit and serve.
(If mousses are to be refrigerated overnight, chill for one hour and then cover each with plastic wrap)