Place the chopped chocolate in a heat-proof bowl (or double boiler) set over a pan of hot (not boiling) water. Heat until the chocolate is melted, stirring occasionally. Remove the bowl of chocolate from the simmering saucepan and set aside to cool.
Using an electric mixer , beat the heavy cream until soft peaks form.
Using the same mixer, combine the granulated sugar and cream cheese in a larger bowl and beat until smooth and well blended.
Add the cooled chocolate and mix until blended. The mixture will stiffen up a bit, but keep mixing until it comes together.
Add the whipped cream to the chocolate mixture and mix on low speed until well combined.
Add the Baileys and vanilla and blend on low speed for a couple more minutes until incorporated. Scrape sides of the bowl down occasionally.
Spoon the cheesecake mixture into the cake pan. Smooth out the top and cover with plastic wrap. Chill until firm; at least 2 hours or overnight.
To serve, carefully remove sides of the pan. Transfer to a serving plate. Cut into slices using a hot, dry knife. Serve immediately garnished with whipped cream and/or strawberries.