For the Crust:
2 cups graham cracker crumbs
2 tablespoons sugar
1/2 cup butter, melted

For the Filling:
3 8-ounce packages cream cheese, at room temperature
1 1/2 cups sugar
4 eggs, at room temperature
1 teaspoon good vanilla extract
1/2 cup butter, melted and cooled
3 ounces good dark chocolate, melted
1/4 cup Kahlua liqueur, or other coffee-flavored liqueur
1 pint sour cream

Prepare a 9- or 10-inch springform pan by wrapping the bottom and sides of the pan with foil. Preheat the oven to 350 degrees Fahrenheit.

For the crust, combine graham cracker crumbs, 2 tablespoons sugar and 1/2 cup melted butter. Mix until well combined. Press into the bottom and halfway up the sides of the prepared springform pan. Set aside.

For the filling, whip the room-temperature cream cheese until fluffy, about 2 to 3 minutes. Add in the 1 1/2 cups sugar, and mix until well combined. Add in the eggs, one at a time, mixing well after each addition. Add in the vanilla, melted 1/2 cup butter, melted chocolate and Kahlua. Mix on low speed for 1 minute, then mix well on medium-high speed for about 3 minutes. Add the sour cream to the batter, and mix until well combined, about another 2 minutes. The batter should be creamy and fluffy.

Pour the cheesecake batter over the crust in the springform pan. Place the springform pan inside a larger roasting pan or cake pan (I use my large lasagna pan). Pour boiling water into the roasting pan until it is halfway up the sides of the springform pan.

Bake the cheesecake at 350 degrees Fahrenheit for 1 hour. After 1 hour, turn off the oven, and leave the cheesecake in the oven for an additional hour. This helps keep the top from cracking.

Allow the cheesecake to cool completely in the refrigerator before serving (at least 8 hours or overnight). Top with your choice of fruit toppings (raspberry is awesome) or freshly whipped cream if desired.