1. Preheat oven to 350°F (180°C). Line baking sheets with parchment paper or silicone baking mats. Set aside.
2. Combine the flour, baking soda and salt in a medium sized bowl and set aside.
3. Cream the butter, sugar and lemon zest together in a large mixer bowl on medium speed for 3-4 minutes, until light in color and fluffy. You should be able to see the change in color and texture happen and know it’s ready.
4. Add the eggs one at a time, mixing until well combined between each addition.
5. Add the vanilla extract and ricotta and mix until well combined.
6. Slowly add the flour mixture and stir until just combined. Do not over mix.
7. If you’d like to chill the cookie dough (which makes it a easier to work with), cover the bowl with plastic wrap and refrigerate for about 2 hours or up to two days. You don’t have to chill the dough though. It doesn’t really change the outcome.
8. Drop tablespoon sized balls (no larger or they will spread too much) of cookie dough onto the cookie sheet and gently shape into a ball shape.
9. Bake for 9-12 minutes or until the bottoms of the cookies are lightly golden.
10. Cool cookies on the cookie sheet for 2-3 minutes, then remove to a cooling rack to cool completely.
11. To make the icing, whisk the powdered sugar, milk, butter and vanilla extract together in a small bowl.
12. Turn the cookies upside down, one at a time, and dip the tops of them into the icing.
13. Turn the cookies over and add sprinkles. Allow to dry. The icing will crust over, but doesn’t dry hard.
14. Store the cookies in an airtight container. The sprinkles will likely bleed after sitting overnight, so if you want the presentation to be nice, I’d suggest adding the icing and sprinkles shortly before serving. The icing also starts to wrinkle after a day or two. Cookies are best for about 4-5 days.