1. 1. Prepare Your Pan: Preheat oven to 325°F (160°C). Lightly grease a 9-inch springform pan. If desired, wrap the outside bottom with foil to prevent leaks.

2. 2. Make the Crust: In a medium bowl, combine graham cracker crumbs, melted butter, and granulated sweetener. Stir until mixture resembles wet sand. Press firmly into the bottom of the prepared pan. Bake for 8-10 minutes, then cool slightly.

3. 3. Prepare the Filling Base: In a large bowl, beat softened cream cheese with an electric mixer on medium speed until smooth and creamy. Scrape down sides as needed.

4. 4. Add Remaining Wet Ingredients: Add Greek yogurt, granulated sweetener, orange juice, vanilla extract, and salt. Beat on medium until well combined and smooth.

5. 5. Incorporate Dry Ingredients: Reduce mixer speed to low. Gradually add vanilla protein powder and orange zest, mixing just until incorporated. Do not overmix.

6. 6. Add the Egg: Add the egg and beat on low just until fully incorporated. Scrape bowl once more.

7. 7. Pour and Bake: Pour filling over cooled crust. Tap pan on counter to release air bubbles. Bake for 50-60 minutes, until edges are set but center still has a slight wobble.

8. 8. Cool and Chill: Turn off oven, prop door open slightly, and leave cheesecake inside for 1 hour. Then remove and cool completely on a wire rack to room temperature. Cover loosely with plastic wrap and refrigerate for at least 4-6 hours, preferably overnight.

9. 9. Garnish and Serve: Remove springform pan sides. Top with sugar-free whipped topping and extra orange zest. Slice and serve chilled.