In the bowl of a stand mixer fitted with the paddle attachment, beat butter and sugar at medium speed until fluffy, 3 to 4 minutes, stopping to scrape sides of bowl. Add eggs, one at a time, beating well after each addition. Add ricotta, lemon zest, and vanilla, beating just until combined.

In a medium bowl, whisk together flour, poppy seeds, baking powder, and salt. With mixer on low speed, gradually add flour mixture to butter mixture, beating just until combined and stopping to scrape sides of bowl. (Dough will be sticky.) Cover with plastic wrap; refrigerate for 1 hour.

Preheat oven to 350°F (180°C). Line rimmed baking sheets with parchment paper.

Using a 1½-tablespoon spring-loaded scoop, scoop dough (about 32 grams each), and place 2 inches apart on prepared pans.

Bake until lightly browned, 12 to 14 minutes. Let cool on pans for 5 minutes. Remove from pans, and let cool completely on wire racks.

Spread Cream Cheese Glaze onto cooled cookies; garnish with lemon zest and poppy seeds, if desired. Store in an airtight container for up to 3 days.