Chill your tools: Place a mixing bowl and whisk or beaters in the fridge for 10 minutes. Cold equipment helps the cream whip faster.
Whip the cream: In the chilled bowl, beat the heavy cream to medium-stiff peaks.
Don’t overbeat. Set aside.
Blend the base: In a separate bowl, beat the softened cream cheese until smooth and fluffy. Add the powdered sweetener, vanilla, salt, and lemon extract if using.
Mix until creamy.
Add the lemon: Beat in the lemon zest and lemon juice. Start with 3 tablespoons of juice, then taste and adjust the sweetness or tartness.
Fold gently: Add one-third of the whipped cream to the lemon-cream cheese mixture and fold to lighten. Fold in the remaining whipped cream in two additions until smooth and airy.
Taste and adjust: If you’d like it sweeter or more tart, sprinkle in a little more powdered sweetener or a touch of lemon juice.
Fold gently to incorporate.
Chill to set: Spoon into serving glasses or ramekins. Refrigerate for at least 1 hour for best texture.
Garnish and serve: Top with a pinch of zest, a few raspberries, or mint. Serve cold.