Preheat oven to 325 degrees F.
In a large bowl, beat cream cheese for 1 minute. Add sugar, salt, cocoa, and flour, mix until completely combined and there are no lumps. Scrape down the sides of the bowl with a spatula.
With the mixer on low, add the eggs, one at a time, and beat until just mixed through, do not to over-beat. Scrape down the sides of the bowl with a spatula.
Add sour cream and Baileys, beat until mixed through.
Add the cooled melted chocolate, stopping to scrape the sides and bottom of the bowl with a spatula.
Pour the batter on top of the brownie layer in the prepared pan. Level the top with a spatula.
Place the springform pan in a large roasting pan, that is deep enough to add water to it. Pour HOT water into the roasting pan, about halfway up the sides of the springform pan.
Transfer the cheesecake into the preheated oven and bake it for 50-60 minutes. Or until the cheesecake is just slightly wobbly in the center, but puffy and settled on the sides.
Turn off the oven and crack open the door. Cool cheesecake completely in the open oven.
Once completely cooled remove from the oven and refrigerate for at least 5-6 hours.
Run a butter knife around the edges to release it from the pan. Store in the fridge until ready to serve.