Preheat oven to 350°F (180°C). Spray an 8-inch springform pan with baking spray with flour.

For crust: In the work bowl of a food processor, place cookies with filling and candies; pulse until finely ground. Add melted butter; pulse until combined. Press mixture into bottom and up sides of prepared pan. Freeze 10 minutes.

Top with a piece of parchment paper, letting ends extend over edges of plate. Add pie weights, filling about half way up sides of pan. Bake until set and fragrant, 10 to 12 minutes. Carefully remove parchment and pie weights. (If sides dipped any during the baking process, use the sides of a measuring cup to gently press back into place while crust is still warm). Let cool on a wire rack for 30 minutes. Wrap bottom and sides of pan in a layer of heavy-duty foil; place in a large oven bag, tucking ends so bag is flush with top edge of pan. (If you do not use an oven bag, wrap in a double layer of foil.) Reduce oven temperature to 325°F (170°C), and position oven rack in bottom third of oven.

For filling: In the top of a double boiler, place chocolate. Cook over simmering water, stirring frequently, until melted. Remove from heat, and let cool slightly (95°F/35°C to 100°F/37°C), about 10 minutes.

In a medium bowl, whisk together sugar and cocoa.

In the bowl of a stand mixer fitted with the paddle attachment, beat cream cheese at medium speed until smooth and creamy, 1 to 2 minutes, stopping to scrape sides of bowl. Add sugar mixture and extracts; beat at medium-low speed until sugar is melted and mixture is smooth. With mixer on low speed, add eggs, one at a time, beating just until combined after each addition and stopping to scrape sides of bowl. Beat in cooled chocolate until smooth, stopping to scrape sides of bowl. Pour filling into prepared crust. Transfer springform pan to a large roasting pan; place in oven. Pour enough water into roasting pan to come 1 inch up sides of springform pan.

Bake until edges are set but center is slightly jiggly, about 1 hour. Let cool in pan on a wire rack for 1½ to 2 hours. Refrigerate in pan on a wire rack overnight, loosely covering with foil only when completely cool to prevent condensation from forming on top of cheesecake.

Carefully remove cooled cheesecake from pan, and transfer to a serving plate. Top with marshmallows, if desired. Using a handheld kitchen torch, brown marshmallows, watching carefully. Top with candies, if desired.