Preheat oven to 325°F (165°C) and lightly grease a 4-inch springform pan or small ramekin.
Mix the almond flour, melted grass-fed butter, and a pinch of cinnamon in a small bowl until it reaches a sandy consistency.
Press the almond mixture firmly into the bottom of the prepared pan to form an even crust.
In a separate bowl, whisk together the Greek yogurt, vanilla protein powder, egg whites, honey, and vanilla extract until completely smooth.
Pour the yogurt filling over the crust and smooth the top with a spatula.
Bake for 25 to 30 minutes, or until the edges are set but the center still has a slight jiggle.
Allow the cheesecake to cool at room temperature for 30 minutes, then refrigerate for at least 2 hours to firm up.
Top with the mixed berries just before serving for a fresh, juicy finish.