Here's what I use....
7 oz chocolate cookie wafers (approx 28 cookies)
1/2 cup toasted hazelnuts
2 tbl sugar
1/4 cup (1/2 stick) melted unsalted butter
1 6 oz pkg semisweet chocolate chips
2 8 oz pkg cream cheese at room temp
1 cup sugar
4 large eggs at room temp
1/2 cup sour cream
2 tsp vanilla
1/4 tsp grated (or ground) nutmeg
1/4 tsp grated lemon peel
1 8 oz pkg cream cheese at room temp
1/2 cup powdered sugar
1/4 cup sour cream
2 tbl Frangelico or Cognac
1 tsp vanilla
Preheat oven to 325° with rack in the middle of oven. Lightly butter 9" springform pan (or 9" glass baking dish, 1" deep) Pulse cookies, nuts and sugar in a food processor until finely ground, add butter and process until well blended. Press crumb mixture into bottom of pan and 1" up sides.
Melt chocolate chips in heavy small saucepan (or a double boiler) over very low heat, stirring constantly. Remove from heat. In the bowl of a stand mixer or in a large bowl using an electric hand mixer, beat cream cheese until light and fluffy. Beat in sugar gradually. Add 1 egg at a time, beating until incorporated after each addition. Add sour cream, vanilla nutmeg and lemon zest and beat until just blended. Pour 1/2 of batter into med bowl, add melted chocolate and mix well.
Pour all but 2 tbl chocolate batter into prepared crust and cover with plain batter. Use a knife tip to swirl batters together. Drizzle with remaining 2 tbl chocolate batter. Bake until toothpick inserted in center comes out clean, (approx 1 hour). Cool completely on rack, cover with plastic and refrigerate overnight. (Can be prepared up to 2 days ahead, covered & chilled.
If using the topping:
Beat cream cheese, sugar, sour cream, Frangelico and vanilla in medium bowl with electric mixer until smooth. Transfer to pastry bag fitted with medium star tip & pipe decorative border around edge of cake (or you can always use the good old makeshift ziplock pastry bag with the corner chopped off) Topping can be prepared 8 hours ahead & chilled.
***This is another version (it's sooo good)
Espresso & Chocolate Swirl Cheesecake
9 oz pkg chocolate wafer cookies
6 tbl (3/4 stick) unsalted butter, melted & cooled before using
2 tbl instant espresso
1 tbl water
3 8 oz pkg cream cheese at room temperature
1 cup sugar
3 large eggs
1/4 cup (1/2 stick) unsalted butter, melted & cooled
1 tbl finely ground coffee
6 oz bittersweet (but not unsweetened) or semisweet chocolate, chopped
1/4 cup whipping cream
Preheat oven to 400° with rack positioned in middle. Grind cookies in processor. Add butter and pulse until crumbs are moist. Press crumbs on bottom and 1 1/2 inches up sides of 9" springform pan. Wrap outside of pan with aluminum foil.
In a small bowl, dissolve instant espresso in 1 tbl water. Use an electric mix to beat cream cheese in large bowl until smooth. Add sugar and continue beating until light and fluffy. Add eggs 1 at a time, beating well to incorporate after each addition. Mix in espresso mixture, butter and ground coffee beans.
Combine chocolate and cream in heavy small saucepan and stir over low heat until chocolate melts. Pour half of cheese filling (2 1/2 cups-ish) into prepared crust. Drop 5 tbl melted chocolate mixture by tbl around edge of filling, spacing evenly. Use knife tip to swirl chocolate into filling. Pour remaining cheese filling over carefully. Drop remaining chocolate mixture by tablespoons into center 6 inches of filling, spacing evenly. Swirl mixtures together using tip of knife.
Bake cheesecake until edges are puffed and beginning to crack and top is golden brown, approx 40 min (center will not be set). Cool on rack. Chill overnight. Can be prepared up to 3 days ahead
Run small sharp knife around edge of pan to loosen cheesecake. Release pan sides. Let stand at room temperature 30 minutes. Transfer to platter and serve.
Hope that helps! Good luck!