In a medium bowl, whisk together the flour, salt, baking soda, and baking powder. Add this dry mixture to the mixer bowl, and incorporate on low speed to form a soft dough.
In the bowl of an electric mixer fitted with the paddle attachment, cream the butter, sugar, and lemon zest until fluffy. Add the egg, ricotta, lemon zest, lemon juice, and vanilla, one ingredient at a time, beating after each addition and scraping down the sides of the bowl as needed.
Cover the bowl and refrigerate at least 1 hour.
Preheat the oven to 350ºF. Line a couple of baking sheets with parchment. Place the icing sugar in a small bowl and the granulated sugar in another small bowl.
Portion out dough into large scoops using a disher ( about 40–45 grams dough per cookie). Roll each scoop into a ball very quickly (dough is soft and sticky). Drop the ball into the bowl of granulated sugar, then roll it around to coat it completely. Transfer the ball to the bowl of icing sugar and roll it around to coat it. Transfer to the prepared baking sheet. Repeat with remaining dough, spacing cookies about 1 ½ inches apart to allow for spread. Fit about 6 cookies per half-sheet pan.
Bake cookies 1 sheet at a time until cracked and set (about 14–16 minutes per cookie). Let cool on pan 2 minutes before transferring to a wire wrack to cool completely.
Notes
Use fresh lemons for the zest and juice to create the brightest lemon flavour.
You need about 2 lemons to get enough juice and zest for this recipe. Obviously, this depends on the lemons and the seasons. Use a microplane to make finer zest.
For even more lemon flavour, you may try to use lemon extract, oil, or even lemon emulsion. Remember with these, a little goes a long way!
I have tested this recipe with full-fat traditional ricotta and low fat. Both work.
If the ricotta has a lot of water, consider straining some of it off before baking with it.
The dough is sticky. Make sure to chill it for 2 hours and use a disher to portion out the dough more easily. Once you coat the scoops of cookie dough in granulated sugar, they will be easier to handle.
For a brighter yellow cookie dough, use yellow food colouring (either a dab of a gel colour or a couple of drops of a liquid food colour).
Space out the cookies on the half-sheet pans. I bake six cookies at a time to ensure they have enough airflow.