Preheat oven to 325°F (160°C) and line a 9-inch springform pan with parchment paper.
Beat softened cream cheese until smooth and fluffy.
Add erythritol and vanilla extract, mixing until fully combined.
Add eggs one at a time, mixing gently to avoid cracks.
Fold in sour cream until smooth.
Press almond flour into the pan if making a crust.
Pour cheesecake batter into pan and bake 40–50 mins until edges are set, center slightly jiggly.
Let cool, then chill at least 3 hours (overnight recommended).
Add optional toppings, slice, and serve.