In a large bowl whisk together the flour, baking powder and salt. Set aside.
In the stand up mixer or large bowl, beat the butter and sugar until light and fluffy 3-4 minutes. Then add the egg and beat together (speed 2), while still beating add the discard, ricotta, zest and vanilla and combine.
On low speed add the flour mixture and beat just until combined. Scrape the bowl down, make sure there is no flour under the batter that hasn't been mixed in. Cover with plastic wrap and refrigerate for 1 hour.
Pre-heat the oven to 350F (180C). Line 1-2 cookie sheets with parchment paper.
Remove the dough from the fridge and drop by spoonfuls on the prepared cookie sheets, bake for 15-17 minutes until lightly golden. Let cool for about 3-5 minutes on the cookie sheets then move to a wire rack. Drizzle the cookies with the glaze when completely cool if desired. Or dust with powdered sugar.
LEMON GLAZE
In a medium bowl whisk together the icing sugar, juice and zest. If too thick add more lemon juice or milk, if too think add more powdered sugar.
Notes
What is Sourdough Starter Discard?
Making sourdough isn't hard by any means but it is a process. To begin, you need to start by fermenting the dough (flour and water) naturally over a period of days in a warm area. Eventually, you will discard about half of the starter to leave room to add more flour and water and continue the process. The discarded half can then be used for all kinds of delicious recipes, like this one.
Can I use another citrus flavour?
Yes! These can be made using lemon, lime, and even orange. In fact, switch it up once in a while. Maybe on special occasions, add some sprinkles on top!
What if the glaze is too thick?
If you find the glaze too thick, add a little more lemon juice or milk. If you find it too thin, add a little more powdered sugar.
How to store Lemon Ricotta Cookies
If they haven't all been eaten by the end of the day, you can store them in an airtight container in the fridge for up to 3 days. They also freeze well for up to 3 months, keeping in mind the glaze may not be the same consistency it once was, so it is best to freeze them unglazed. Thaw them overnight at room temperature.