Prep the pan and oven. Preheat the oven to 325°F (163°C).
Line a 12-cup muffin tin with paper liners. Lightly mist the liners with nonstick spray to prevent sticking.
Make the crust. In a bowl, mix almond flour, sweetener, melted butter, cinnamon, and a pinch of salt. The mixture should look like damp sand that clumps when pressed.
Press the crust. Divide the crust evenly among the liners (about 1 tablespoon each).
Press firmly with the bottom of a shot glass or spoon to compact. Bake for 6–7 minutes, until lightly set and fragrant. Let cool slightly while you make the filling.
Beat the filling. In a mixing bowl, beat softened cream cheese until smooth and lump-free.
Add Greek yogurt, sweetener, vanilla, protein powder, and salt. Beat again until creamy. Scrape the bowl.
Add the egg and mix on low just until incorporated. Do not overmix.
Fill the cups. Spoon the cheesecake batter over the crusts, filling each liner about 3/4 full. Tap the pan gently on the counter to pop any air bubbles.
Bake. Bake at 325°F for 14–18 minutes. The edges should look set and the centers slightly wobbly.
Avoid browning the tops.
Cool gradually. Turn off the oven, crack the door slightly, and let the cheesecakes sit for 10 minutes. Move the pan to a wire rack to cool to room temp, then refrigerate for at least 2 hours, preferably overnight.
Make the “graham” sprinkle. Stir together 1 tablespoon almond flour and 1/2 teaspoon cinnamon. This adds a toasty, graham-like finish with minimal carbs.
Add the chocolate. Melt the sugar-free chocolate in short bursts in the microwave, stirring every 20–30 seconds.
Spoon or drizzle a small amount over each chilled cheesecake cup.
Toast the marshmallows. Place a few mini sugar-free marshmallows on each cup. Use a kitchen torch to lightly toast until golden and gooey. If you don’t have a torch, set the cups on a baking sheet and broil for 30–60 seconds, watching closely. Don’t walk away.
Finish and serve. Sprinkle on the almond flour–cinnamon “graham,” add a pinch of flaky salt if you like, and let the chocolate set for a couple of minutes.
Serve chilled or slightly cool.