Melt the Butter: In a small saucepan, gently melt the butter over low heat until fully liquefied. Allow it to cool to room temperature.

Mix Sugar and Zest: In a large mixing bowl, combine granulated sugar with lemon zest, rubbing until it resembles wet sand.

Combine Wet Ingredients: Add cooled butter to the sugar mixture along with egg and vanilla extract, whisk until smooth.

Mix Dry Ingredients: In a separate bowl, whisk together flour, baking powder, baking soda, poppy seeds, and salt.

Combine Mixtures: Gradually mix dry ingredients into wet mixture, stirring gently until just combined.

Scoop Dough: Form balls of dough and place them on a lined baking tray, chill for 30 minutes.

Preheat Oven: Preheat oven to 355°F (180°C).

Bake Cookies: Bake cookies for 10-11 minutes until edges are set and centers are slightly soft. Cool on tray for 3 minutes.

Make Frosting: Combine cream cheese, powdered sugar, and heavy cream in a bowl. Whip until stiff peaks form.

Frost Cookies: Once cookies are cool, pipe or spread the frosting over each cookie, garnishing with extra poppy seeds or lemon zest as desired.