Preheat oven to 325°F (165°C) and line a standard muffin tin with 12 paper liners.

In a small bowl, combine graham cracker crumbs and melted butter until the mixture resembles wet sand.

Press approximately 1 tablespoon of the crust mixture into the bottom of each muffin liner.

In a medium mixing bowl, beat the softened cream cheese and sweetener until smooth and creamy.

Incorporate the pumpkin puree, protein powder, pumpkin pie spice, and vanilla extract until fully blended.

Add the egg and mix on low speed just until combined to avoid aerating the batter.

Distribute the cheesecake batter evenly across the 12 muffin liners.

Bake for 22 to 25 minutes or until the edges are firm but the centers remain slightly jiggly.

Cool at room temperature for 30 minutes, then refrigerate for at least 2 hours to allow the protein to set the structure fully.