Preheat oven to 325 degrees F / 163 degrees C.
Grate zest from lemons. Set aside. Juice lemons and strain out seeds. Set lemon juice aside.
In a large bowl, combine butter, monk fruit sweetener and egg. Stir to combine.
Add ricotta, 1 tsp lemon zest and lemon juice. Stir to combine
Add almond flour, collagen powder, baking powder, baking soda, sea salt and vanilla extract. Stir to combine ingredients. Once dough is combined, cover with plastic wrap and transfer to refrigerator. Chill at least 30 minutes.
For icing, combine sweetener, heavy cream and vanilla extract in a small bowl. Stir until sweetener is dissolved. Add a teaspoon of lemon juice at a time and stir, until icing is runny.
Remove the dough from refrigerator and portion into heaping teaspoon-sized balls. Place on baking sheet and bake for 12 to 14 minutes until set.
Remove cookies from oven and cool. Drizzle with icing and sprinkle with remaining zest.