01 - Place softened cream cheese in a medium mixing bowl. Using a hand mixer on medium speed, beat until completely smooth and creamy, approximately 2 minutes.
02 - Add powdered erythritol and vanilla extract to the cream cheese. Continue beating on medium-high speed until fully incorporated and no sweetener granules remain visible, about 1 minute.
03 - While mixer runs on medium-low speed, gradually drizzle in heavy whipping cream. Increase speed to high and continue whipping until mixture becomes light, airy, and holds soft peaks, approximately 3 to 4 minutes. Fold in lemon zest if using.
04 - Divide cheesecake fluff evenly among four dessert glasses or serving bowls. Top with fresh berries and chopped nuts if desired. Serve immediately for a mousse-like texture, or refrigerate for up to 48 hours for a firmer consistency.