85 grams butter
125 grams crushed digestive biscuits or graham crackers
4 tablespoons granulated sugar
1 tablespoon cocoa
13/4 cups granulated sugar
1 teaspoon vanilla extract
5 large eggs
3 egg yolks
1/2 teaspoon salt
21/2 pounds cream cheese
4 tablespoons all-purpose flour
1/4 cup heavy cream
1/4 cup Baileys Irish Cream liqueur
1 teaspoon instant coffee crystals
1 tablespoon cocoa
2 tablespoons warm water
Butter an 8-inch or 9-inch springform pan and then line its bottom and sides with parchment paper. Butter the paper lining the sides of the springform. Set aside while the ingredients come to room temperature.
Melt the butter and crush the graham crackers or digestive biscuits very finely. Put them in a heatproof bowl and stir in the cocoa and granulated sugar. Melt the butter on the stove or in the microwave and add to the mixture. Stir well together with a fork and allow to cool.
When the crust mixture is cooled, press it into the bottom of the springform pan and half an inch or so up the sides. Preheat the oven to 375 F and bake in the preheated oven for 7 minutes. When finished, set aside to cool completely.
In a large electric mixer’s bowl put in half the cream cheese, half the sugar, and two tablespoons of the flour.
Beat well, then add the rest of the cream cheese, the rest of the sugar, vanilla, cream, and one tablespoon of the flour. (Reserve the remaining tablespoon.)
One at a time, beat in each of the eggs. Make sure each one is beaten in very well before adding the next. Do the same with two of the egg yolks; reserve one.
When completely mixed, pour half the cheesecake batter into a second bowl. In a third, smaller bowl, add hot water to the instant coffee crystals; mix well until dissolved. Add the cocoa and whisk until well blended into the coffee mixture. Add the final tablespoon of flour and the final egg yolk and whisk well again until completely blended. Finally, add the Baileys and once again whisk lightly until completely blended.
Add this mixture to one of the bowls of cheesecake batter, and stir well until it is completely mixed into the second bowl.
By large spoonfuls, take turns spooning the two mixtures into the springform pan. When the pan is full, carefully draw a knife through the mixture a number of times, both vertically and horizontally, to produce the marbling effect.
Preheat the oven to 475 F. Place the cheesecake carefully on the center rack of the oven and bake at this temperature for 15 minutes. Then reduce the heat to 400 F and bake for another 60 minutes. Open the oven, and quickly (wearing an oven mitt) jiggle the springform pan a little to check the cake’s texture. If it is still “wiggly” or loose, it needs a little more time. Allow it to bake for another 10 minutes; then turn the oven off. Allow the cheesecake to sit in the residual heat for another half hour. Then remove and cool on a rack.
When completely cool, refrigerate the cheesecake overnight. Remove the cheesecake from the fridge, carefully unclamp and remove the springform’s ring, and peel off the baking parchment. Slice to serve.