Preheat the oven.

Combine Oreo cookie crumbs with melted butter and press into the bottom of a springform pan.

In a saucepan, heat Guinness Stout Beer and chopped semi sweet chocolate until melted and smooth.

In a mixing bowl, blend softened cream cheese and sugar until creamy.

Add cocoa powder, sour cream, vanilla extract, and mix well.

Incorporate eggs one at a time, mixing after each addition.

Fold in melted chocolate mixture and white chocolate chips.

Pour cheesecake batter over crust and smooth the top.

Bake until set, then let cool.

Combine heavy whipping cream, Baileys Irish Cream, and powdered sugar, whisk until stiff peaks form.

Spread whipped mixture over cooled cheesecake.

Chill before serving.