Prep your pan and oven. Heat the oven to 325°F (163°C).
Line the bottom of a 9-inch springform pan with parchment and lightly coat the sides with cooking spray. Wrap the outside of the pan with a double layer of foil to prevent moisture or leaks.
Make the crust. In a bowl, mix crumbs, cocoa, sweetener, melted butter, and a pinch of salt until it looks like damp sand. Press firmly into the bottom of the pan.
Use a flat-bottomed cup to pack it tightly. Bake for 8 minutes, then cool slightly.
Beat the cream cheese. With a mixer on medium-low, beat the cream cheese until smooth, about 1–2 minutes. Scrape the bowl to remove any lumps.
Add yogurt, sweetener, and vanilla. Mix in the Greek yogurt, granulated sweetener, and vanilla until smooth.
Keep the speed low to avoid whipping too much air.
Blend in dry ingredients. Whisk protein powder, cornstarch, and salt together in a small bowl. Add to the batter and mix on low just until incorporated.
Add eggs last. Beat in the eggs one at a time, mixing on low until the batter is silky. Stop as soon as the mixture looks uniform.
Assemble and smooth. Pour the filling over the crust.
Tap the pan gently on the counter a few times to release air bubbles. Run a thin spatula across the top to even it out.
Create a steam bath. Place the springform pan in a large roasting pan. Fill the roasting pan with hot water halfway up the sides of the springform.
This helps prevent cracks.
Bake. Bake for 45–55 minutes. The edges should be set and the center slightly wobbly, like soft Jell-O. Avoid overbaking.
Cool gradually. Turn off the oven, crack the door, and let the cheesecake sit inside for 30 minutes.
Then remove it from the water bath and cool on a rack until room temperature.
Chill to set. Cover and refrigerate for at least 6 hours, preferably overnight. Patience pays off here.
Top it. Once chilled and set, release the springform. Drizzle the caramel over the top, then the melted chocolate.
Sprinkle toasted pecans and a pinch of flaky sea salt if you like.
Slice cleanly. Use a hot, dry knife (dip in hot water and wipe) for neat slices.