That Bailey's Marbled Cheesecake

This is the one I made for the cocktail party the other day.
I found the original recipe on the net but wanted to add some stuff to it, so here it is. I usually don't write the recipes down so it's approximate but hope this works for you.

Bailey's Marbled Cheesecake

1/2 cup butter, melted
2 cups biscuits(I used vanilla and chocolate ones)
500g cream cheese, softened
1 cup sugar
3 eggs
250g sour light cream
1 teaspoon vanilla extract
1/2 cup Baileys Irish cream
100g dark chocolate, melted

1. Line a 9-inch springform tin with baking paper. For the crust, roll the biscuits with a rolling pin into crumbs and combine them with melted butter. Press firmly evenly over bottom of the tin.

2. Mix cream cheese with sugar. Beat eggs one at a time. Add vanilla, sour cream and Baileys and mix well.

3. Take about 1/4 of the mixture into the smaller bowl and mix it with the melted chocolate.

4. Pour the plain mixture into the prepared tin and then pour the chocolate mixture on top. Make a marbled design by gently swirling batter with small knife.

5. Bake in a preheated 160 degrees oven for 1 hour. Refrigerate the cake overnight.