Mix crust ingredients in a bowl and press firmly into a tart pan.
Refrigerate crust for at least 20 minutes to firm up.
In a separate bowl, mix Greek yogurt, sweetener, vanilla, lemon zest, and cream cheese until smooth.
Spread the yogurt mixture evenly into the chilled crust.
Refrigerate for 4 hours or overnight to set.
Top with fresh berries right before serving.
Slice and enjoy cold.
