To make the chocolate layer, place chocolate and butter in a large glass dish (you will be adding the eggs, sugar, and flour to it later) and microwave 1.5 minutes. The chocolate may hold its shape when you remove it from the microwave, but it will be soft, so stir to melt it. If pieces remain after you have stirred it for a while then return to microwave for another few seconds and then stir again until it is fully melted. Be careful not to overheat the chocolate. You are better off starting with less time and reheating than overheating and ruining it.When chocolate has melted add the sugar and vanilla and stir with a whisk to combine.
Let it cool a little and then add the eggs, one at a time, whisking after each addition. Don't add the eggs when the chocolate is hot because it may cook the whites.Once the eggs are mixed in, place the flour in a strainer and sift over the chocolate mixture, a little at a time, mixing it in as you sift it over. Set aside while you prepare the cream cheese layer.For the cream cheese layer, place the cream cheese in a bowl and mix with a hand mixer for a couple of minutes until soft.
Add the sugar and mix to blend it in.
Add egg and beat to incorporate.
Add Bailey's and stir it in.To assemble, spray an 8" square baking pan with straight sides with non-stick spray, or butter and flour it. You can also line the baking pan with parchment, leaving the edges high so you can lift the entire cake out of the pan.
Pour the chocolate mixture into the pan and tilt it to spread it out evenly.
Pour the cream cheese mixture over it, and with a fork, swirl the layers so some of the chocolate shows on top and the cream cheese layer becomes part of the chocolate layer. Do not over mix - you just want some swirls.
Place in a preheated 350 degree F oven and bake for 35 minutes or until a knife inserted into the center comes out clean. Do not over bake.
Remove from oven and let cool before cutting into squares.
