To make the cookies, in a medium bowl, whisk together the all-purpose flour, almond flour, salt, and baking powder and set aside. In a stand mixer fitted with a paddle, cream together the butter, sugars, and lemon zest (if using) on medium high until pale and fluffy, 3 to 4 minutes, occasionally scraping down the sides of the bowl with a spatula. Add the eggs, one at a time, beating well after each addition, then add the extracts.