Preheat oven to 375 degrees.
In the bowl of a stand mixer (or a large bowl with a hand mixer), cream together the butter and sugar until light and fluffy.
Add the eggs (one at a time) and beat well after each addition, making sure to scrape down the sides of the bowl as needed.
Blend in the ricotta cheese and almond extract.
In a large bowl, whisk together the flour, baking powder, lemon zest, and salt.
Working in increments, slowly add the flour mixture into the ricotta mixture (⅓ at a time), mixing each addition until just combined. *Note - The less you mix, the more tender the cookies will be.
Add the nuts and blend until just combined.
Drop the dough by tablespoons onto parchment lined baking sheets (12-15 per sheet).
Bake for 22-25 minutes in preheated oven, rotating the cookie sheets halfway through baking.
Cool completely on wire rack before ricing.