FOR THE MOUSSE

In a small bowl, sprinkle the powdered gelatin over the water. Let stand for about 5 minutes. Place the chocolate in a medium glass bowl, set aside.

In a saucepan, bring the Guinness, espresso powder and 1/4 cup of heavy cream to a boil. Add the gelatin mixture to the heavy cream mixture and whisk until the gelatin is dissolved. Pour the cream mixture over the chocolate and let sit for 2-3 minutes.

Whisk until the chocolate is melted and the mixture is smooth. Set aside to cool to room temperature.

Whip remaining 1-1/2 cups of heavy cream, powdered sugar and vanilla extract with a mixer fitted with the whisk attachment until stiff peaks form.

Gently fold about a half of the whipped cream into the cooled chocolate mixture until combined. Add the rest of the whipped cream and gently fold into the chocolate mixture.

FOR THE WHIPPED CREAM

To make the whipped cream, whip the heavy cream, Irish Cream, and vanilla extract on high speed with the whisk attachment until stiff peaks form. Put a towel over the bowl, to prevent the cream from splashing out of the bowl.

Scoop the mousse into 6 or 8 small glasses, ramekins or martini glasses, plop some Irish Cream whipped cream on top. Add your favorite thin chocolate wafer cookie to garnish.