8 whole Chocolate Graham crackers,broken into rough pieces
1 Tbsp. Sugar
5 Tbsp. Unsalted butter,melted
5 oz. Semisweet chocolate, chopped
1/4 c. Heavy cream
2 1/2 lbs. (5 8 oz. Bars) cream cheese, cut into 1-inch chunks & softened
1 1/2 c. Sugar
1/8 tsp. Salt
1/3 c. Sour cream
2 tsp. Lemon juice
2 tsp. Vanilla extract
6 large eggs plus 2 large yolks
1 Tbsp. Unsalted butter,melted
1. For crust: Adjust oven rack to lower middle position and heat oven to 325. Process graham cracker pieces in food processor to fine crumbs, 30 sec. Combine graham cracker crumbs and sugar in medium bowl, add melted butter, and toss with fork until evenly moistened. Empty crumbs into 9-inch springform pan and, using bottom of ramekin or dry measuring cup,press crumbs firmly and evenly into bottom of pan,keeping sides clean. Bake crust until fragrant, about 13 minutes. Let cool in pan on wire rack while making filling.
2. Filling: increase oven temperature to 500 degrees. Using stand mixer fitted with paddle,beat cream cheese on med-low about 1 minute. Scrape down bowl. Add 3/4 cup sugar and salt and beat on med-low until combined, about 1minute. Scrape down bowl, then beat in remaining 3/4 cup sugar until combined, about 1minute. Scrape down bowl, add sour cream,lemon juice,and vanilla,and beat on low speed until combined, about 1minute. Scrape down bowl, add egg yolks, beat on med-low until thoroughly combined, about 1minute. Scrape down bowl, add whole eggs,two at a time,beating until thoroughly combined,about 1 minute,scraping down bowl between additions.
3.Chocolate: Melt 5 oz. Chopped semisweet chocolate and 1/4 c heavy cream together in microwave,stirring often,until melted and smooth, 1 to 3 minutes. Set aside and let cool completely.
4. Being careful not to disturb baked crust, brush inside of pan with melted butter and set pan on rimmed baking sheet to catch any spills in case pan leaks. Pour filling onto cooled crust. Drop spoonfuls of cooled chocolate over top of batter. Using butter knife or offset spatula, swirl chocolate into cheesecake batter, creating attractive marble pattern. Bake in 500 degree oven for 10 minutes;without opening oven door,reduce temperature to 200 degrees and continue to bake until cheesecake registers about 150 degrees, about 1 1/2 hours. Let cake cool on wire rack for 5 minutes, then run thin knife around cake to loosen from pan. Let cake continue to cook until barely warm, 3-4 hours. Wrap tightly in plastic wrap and refrigerate until cold, at least 3 hours, best if left for 24 hours. Can be refrigerated for up to 4 days.
5. To unmold, wrap hot dish towel around pan and let stand 1 minute. Remove sides of pan. Slide thin metal spatula between crust and pan bottom to loosen, then slide cake onto serving platter. Let sit at room temperature for 20 minutes before serving.