Whisk the flour, baking powder, baking soda, and salt together in a large bowl. Set aside.

With a handheld or stand mixer fitted with a paddle or whisk attachment, beat the butter and sugar together on high speed until creamy, about 2 minutes. Scrape down the sides and up the bottom of the bowl as needed. With the mixer running on low speed, add the eggs one at a time, then add the ricotta cheese, vanilla extract, almond extract (if using), lemon zest, and lemon juice. Beat on medium-high speed until combined. Scrape down the sides and up the bottom of the bowl as needed. Add the dry ingredients. On low speed, beat everything just until incorporated. Do not overmix. Dough will be very creamy, sticky, and thick. Cover dough tightly with aluminum foil or plastic wrap and chill for 1 hour and up to 2-3 days.

Preheat the oven to 350°F (177°C). Line two large baking sheets with parchment paper or silicone baking mats. (Always recommended for cookies.) Set aside.

Remove cookie dough from the refrigerator. Measure cookies to be 1 Tablespoon of dough each—just use a Tablespoon measuring spoon and your finger to release it onto the sheet. Place 3 inches apart on the baking sheets. Bake for 13-14 minutes or until a cookie springs back when lightly poked with your finger. (That’s how I test them!)

Remove from the oven and allow cookies to cool on the baking sheet for 5 minutes before transferring to a wire rack to cool completely before glazing.

Whisk the confectioners’ sugar and lemon juice together until smooth. Add more confectioners’ sugar to thicken or more lemon juice to thin, if desired. Spoon over cookies. Top with a sliced almond, if desired. If applied lightly, the glaze will set within a couple hours.

Glazed cookies will stay fresh covered at room temperature for 2 days or in the refrigerator for up to 1 week.