Preheat oven to 350°F (175°C). Combine graham cracker crumbs, powdered sugar, and melted butter. Press into the bottom of a baking pan.
In a separate bowl, beat cream cheese and sugar until smooth. Beat in vanilla extract. In a separate bowl, whip heavy cream until stiff peaks form. Gently fold whipped cream and Baileys into the cream cheese mixture.
Pour filling over the crust. Bake for 30 minutes, or until set. Let cool completely before cutting into bars.
Notes
Store leftover bars in the refrigerator for up to 3 days.