• Preheat oven to 350℉. Line baking sheet with parchment paper.
• In a small glass bowl, microwave unsalted butter (¾ cups, i.e. 1 ½ sticks) until melted. Pour into large mixing bowl. Add in granulated sugar (½ cup) and powdered sugar (½ cup) and mix for 10 seconds.
• Add 1 egg + 1 yolk, vanilla extract (2 teaspoons), and lemon extract (½ teaspoon) and mix on medium speed for 20 seconds.
• Turn mixer to low speed, then add baking powder (1 ½ teaspoons), baking soda (½ teaspoon) and salt (¼ teaspoon). Mix for 10 seconds.
• Half cup at a time, add all-purpose flour (2 ½ cups) and mix until flour is just incorporated (about 10-20 seconds). Do not overmix.
• Immediately after mixing, scoop dough into 3-tablespoon sized balls. Lightly flatten each ball before placing on cookie sheet. (Because this has melted butter, do not let the dough sit out before rolling into balls & baking, or your dough will become dry and crumbly.)
• Bake at 350℉ for 8-10 minutes. (The magic number in my oven is 9 minutes) They may look underdone, but they will finish baking on the hot cookie sheet after you take it out of the oven. (Of course, because ovens bake differently use your best judgement to keep them in a minute longer if they look severely underbaked.)
• After removing from oven, allow the cookies to cool on the hot baking sheet for 10 minutes before removing them from cookie sheet.

To make frosting:

• In a large bowl, beat the softened unsalted butter (¼ cup) and cream cheese (4 ounces) on medium speed using a hand or stand mixer (with paddle attachment) for 2-3 minutes (until light and creamy).
• Keeping the mixer on medium speed, slowly add in vanilla extract (1 teaspoon), lemon extract (½ teaspoon), fresh lemon juice (1 tablespoon), and powdered sugar (1 ¼ cups). Once incorporated, turn mixer to high speed and beat for 2 minutes.
• Spread or pipe frosting on cooled cookies and top with sprinkles, if desired!