Prep the pan: Line an 8x8-inch pan or a 9-inch square dish with parchment, leaving an overhang so you can lift the dessert out later.
Make the crust: In a bowl, combine almond flour, powdered sweetener, and salt. Stir in melted butter and vanilla until the mixture looks like damp sand and holds together when pressed.
Press and set: Press the crust firmly and evenly into the lined pan. Use the bottom of a measuring cup to compress it.
Chill in the fridge while you make the filling.
Whip the cream: In a cold bowl, whip the heavy cream to stiff peaks. Set aside.
Beat the cream cheese: In a separate bowl, beat softened cream cheese with powdered sweetener until smooth and fluffy, about 1–2 minutes. No lumps should remain.
Add flavor: Beat in lemon zest, lemon juice, vanilla, and a pinch of salt.
The mixture will loosen slightly—that’s okay.
Fold in the cream: Gently fold the whipped cream into the lemon mixture in two additions. Keep the mixture light and airy.
Assemble: Spread the filling over the chilled crust. Smooth the top with a spatula for a clean finish.
Chill: Cover and refrigerate for at least 4 hours, preferably overnight, until fully set.
Serve: Lift the dessert out using the parchment.
Cut into squares and top with whipped cream, lemon zest, or berries if you like.