Prep the pan: Heat oven to 325°F (160°C). Line the bottom of a 9-inch springform pan with parchment. Lightly spray sides with nonstick spray.
Make the crust: In a bowl, combine crushed cookies, chopped hazelnuts, cocoa, sweetener, salt, and melted butter.
Mix until it resembles damp sand.
Press and pre-bake: Firmly press crust into the pan’s bottom. Bake for 8–10 minutes until set and fragrant. Cool 5 minutes while you make the filling.
Beat the base: In a large bowl, beat softened light cream cheese with sweetener on medium speed until smooth and fluffy, about 2 minutes.
Scrape the bowl.
Add yogurt and flavors: Beat in Greek yogurt, cocoa powder, vanilla, almond extract (if using), and salt until silky. Avoid overmixing.
Add eggs gently: Beat in eggs one at a time on low speed just until combined. Overbeating adds air and can cause cracks.
Swirl in hazelnut: Warm 2 tablespoons chocolate-hazelnut spread until pourable.
Pour cheesecake filling over crust. Drizzle the spread on top and gently swirl with a skewer or knife.
Bake low and slow: Bake at 325°F (160°C) for 35–45 minutes. The edges should be set, and the center should jiggle slightly like gelatin.
Cooling routine: Turn off the oven, crack the door, and let the cheesecake rest inside for 30 minutes.
Move to a rack and cool to room temp.
Chill fully: Cover and refrigerate at least 6 hours, preferably overnight, to set and develop flavor.
Finish and serve: Before serving, warm 2 tablespoons chocolate-hazelnut spread and drizzle over the top. Sprinkle chopped hazelnuts. Slice with a hot, clean knife for neat pieces.