In a high-power blender, combine the ricotta cheese, heavy cream, lemon zest, powdered Besti, and vanilla. Blend for about 1 minute, until smooth and creamy.
If the mixture has trouble blending or is too thick, add more cream, 1 tablespoon at a time, to get the consistency you like. Adjust sweetener to your taste if needed.
In 4 parfait cups, build alternating layers of ricotta whip and berries. (I do 2 layers of each.)
If you like, garnish with whipped cream and sliced almonds.
