Chill a mixing bowl and beaters in the freezer for 10 minutes.
Bloom gelatin by sprinkling it over the cold water. Let stand 5 minutes.
Warm 1/2 cup of the cream until steaming. Pour over chopped chocolate and rest 1 minute.
Whisk until smooth, then mix in cocoa, sugar, and salt until dissolved.
Stir in Baileys and vanilla. Whisk until glossy, then let cool to just warm.
Melt the bloomed gelatin gently in the microwave for a few seconds. Whisk into the chocolate mixture.
Whip the remaining cream in the chilled bowl to soft peaks. Sprinkle in espresso powder and whip to medium peaks.
Fold the whipped cream into the chocolate mixture in two additions until no streaks remain.
Spoon into 6 small glasses. Chill until set, about 2 to 3 hours. Garnish with chocolate shavings.