Preheat your oven to 325°F (160°C). Line two baking sheets with silicone mats or parchment paper – this makes cleanup a breeze!
In a medium bowl, beat the softened butter with the granulated erythritol until nicely combined. Next, whisk in the egg and vanilla extract until the mixture is light and creamy. Gently fold in the ricotta cheese and your chosen citrus zest (orange or lemon).
Add all at once the almond flour, coconut flour, baking powder, baking soda, and salt to the wet mixture. Beat until the dough just comes together – avoid overmixing to keep them tender.
Roll the dough into small, 1-inch balls. Place them about 2 inches apart on your prepared baking sheets. Using the palm of your hand, gently press each ball to flatten it slightly, aiming for about 3/4 inch thick. This helps them bake evenly and prevents too many cracks.
Bake for 15 to 20 minutes, making sure to switch the baking sheets halfway through baking for an even cook. They'll be lightly browned and still very soft when done. Let them cool completely on the pans – patience is key here!
While the cookies cool, prepare your simple glaze. In a medium bowl, whisk together the powdered sweetener, heavy whipping cream, and vanilla extract. Gradually add water, a little at a time, until the glaze is thin enough to easily dip the cookies.
Once the cookies are fully cooled, dip the top of each cookie into the glaze. Turn it right-side up and gently shake off any excess. Place them on a cooling rack. If you're using keto sprinkles, add them now for a festive touch! Let the glazed cookies set for about 1 hour before serving.