In a small saucepan, heat cream over medium heat, stirring occasionally, until a film starts to form on top and an instant-read thermometer registers 180°F (82°C). Remove from heat, and stir in tea. Let stand for 5 minutes. Stain through a fine-mesh sieve, discarding solids. Pour ½ cup (120 grams) chai cream into a small bowl, and let cool to room temperature. Discard any remaining cream.

Preheat oven to 350°F (180°C). Spray bottom of a 9-inch springform pan with baking spray with flour; line bottom of pan with parchment paper.

In a large bowl, stir together ground gingersnap cookies, melted butter, 2 tablespoons (24 grams) sugar, and ¼ teaspoon salt until well combined; using a small straight-sided measuring cup, press mixture into bottom of prepared pan.

Bake until set and fragrant, 10 to 12 minutes; let cool on a wire rack for 30 minutes. Wrap bottom and sides of pan in a double layer of heavy-duty foil; place in a large oven bag, tucking ends so bag is flush with top edge of pan. Reduce oven temperature to 325°F (170°C).

In the bowl of a stand mixer fitted with the paddle attachment, beat cream cheese at medium speed until smooth and creamy, 2 to 3 minutes, stopping to scrape sides of bowl. Add flour, vanilla, remaining 1½ cups (300 grams) sugar, and remaining ¼ teaspoon salt; beat at low speed just until combined. Increase mixer speed to medium, and beat until well combined, 1 to 2 minutes, stopping to scrape sides of bowl. Add eggs, one at a time, beating until combined after each addition. Add chai cream and sour cream; beat at medium-low speed until well combined, 1 to 2 minutes, stopping to scrape sides of bowl. Transfer 2¼ cups (about 470 grams) batter to a medium bowl; add Chai Spice Mix and cocoa, folding just until combined.

Spray sides of prepared pan with baking spray with flour. Pour 2¼ cups (about 470 grams) plain batter onto prepared crust. Pour 1 cup (about 208 grams) chai batter in center of plain batter in pan. Using a spoon, dollop both remaining batters randomly onto surface of batter in pan. Using the tip of a knife, swirl batters together. (To get full marbled effect throughout cake, place knife almost to crust when swirling. Be careful not to bring knife in and out of batter too much; it will create air bubbles on top of cheesecake.)

Position oven rack in bottom third of oven. Place a roasting pan in oven; place springform pan in center of roasting pan. Add hot water to come 1 inch up sides of springform pan.

Bake until edges are set, top looks dry, center is almost set, and an instant-read thermometer inserted in center registers 150°F (66°C) to 155°F (68°C), 1 hour and 30 minutes to 1 hour and 40 minutes. 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 from pan, and transfer to a serving plate. Use a warm dry knife to slice when ready to serve.

In a small bowl, stir together all ingredients. Store in an airtight container for up to 2 months.