In a bowl, combine the flour, baking soda, and salt. Set aside.
In a separate bowl, using a hand mixer, beat together the butter and sugar until combined and creamy. Add the ricotta, and beat until it's completely incorporated.
Add egg and vanilla and beat again with the mixer until well combined. Add lemon zest and lemon juice, and mix that in.
Add the dry ingredients to the wet ingredients and beat on low speed until just combined.
Cover with plastic wrap, and chill in the fridge for at least 2 hours and up to 5 days.
Preheat the oven to 350°F/180°C/160°C fan oven, and line a baking tray with parchment paper or use a silicone mat.
Using a small tablespoon size cookie scoop, drop a tablespoon of dough per cookie onto a lined baking sheet, leaving room for cookies to spread (about 1.5-2 inches).
Bake for 12-14 minutes, or until cookies have set and they're golden brown at the bottom.
Cool on the baking tray for 5 minutes, then carefully transfer cookies to a cooling rack. Allow to cool completely before adding the glaze.