Prep the pan: Wrap the outside of a 9-inch springform pan with two layers of heavy-duty foil, sealing the bottom and sides. Lightly grease the inside. Preheat oven to 325°F (165°C).
Make the crust: Pulse cookies to fine crumbs.
Add melted butter and a pinch of salt; pulse until the texture resembles wet sand. Press firmly into the bottom of the pan. Bake for 8 minutes, then cool slightly.
Warm the dairy: Let cream cheese and yogurt sit at room temp 30–45 minutes.
This prevents lumps and overmixing later.
Mix the filling base: In a large bowl, beat cream cheese on medium-low until smooth, about 1 minute. Add sweetener blend, sugar, salt, and cornstarch; mix just until combined, scraping the bowl.
Add yogurt and vanilla: Beat in Greek yogurt and vanilla on low until smooth. Avoid whipping too much air into the batter.
Incorporate protein: Whisk protein powder to break up clumps, then add to the bowl.
Mix on low until fully blended and satiny.
Add eggs: Beat in eggs and egg whites one at a time on low, mixing just until incorporated. Stop when the batter is uniform and glossy.
Fold in cookies: Gently fold chopped cookies into the batter with a spatula. Don’t over-stir or the crumbs will gray out the filling.
Set up the water bath: Place the foil-wrapped pan in a large roasting pan.
Pour the filling over the crust and smooth the top. Carefully add hot water to the roasting pan to reach halfway up the sides of the springform.
Bake: Bake at 325°F (165°C) for 50–60 minutes. The edges should be set and the center should wobble slightly like gelatin.
Cool gradually: Turn off the oven, crack the door, and let the cheesecake rest inside for 45 minutes.
Remove from the bath, discard foil, and cool to room temperature.
Chill: Cover and refrigerate at least 6 hours, preferably overnight, to fully set and develop flavor.
Optional topping: Stir yogurt, powdered sweetener, and vanilla. Spread a thin layer over the chilled cheesecake and add a few crushed cookies for a clean cookies-and-cream look.
Slice and serve: Run a thin knife around the edge before unclipping the pan. Use a hot, clean knife for neat slices.