Preheat oven to 325°F and line two mini muffin tins with 24 paper liners.
Mix together almond flour, melted butter, erythritol, and cinnamon until well combined and crumbly.
Press about 1 teaspoon of crust mixture into the bottom of each liner, pressing down firmly with your fingers or the back of a spoon.
Beat cream cheese and sweetener with an electric mixer until smooth and fluffy, about 2 minutes.
Add eggs one at a time, beating well after each addition. Mix in sour cream, vanilla, and lemon zest if using.
Spoon or pipe filling over each crust, filling each liner about ¾ full.
Bake for 18-20 minutes until centers are just set but still slightly jiggly.
Turn off oven and crack the door open. Let cheesecake bites cool in the oven for 15 minutes to prevent cracking.
Remove from oven and cool completely, then refrigerate for at least 2 hours before serving. Top with sugar-free whipped cream and fresh berries just before serving.