01 -
Beat the softened unsalted butter and granulated sugar together in a large bowl until light and fluffy, approximately 2-3 minutes to incorporate air.
02 -
Mix in the egg yolk and vanilla extract thoroughly to create a smooth, homogeneous mixture.
03 -
Gradually add the all-purpose flour and salt, mixing until just combined to avoid overworking the dough and ensure tenderness.
04 -
Roll dough into 1-inch balls, arrange on a parchment-lined baking sheet spaced 2 inches apart, then chill for 30 minutes to maintain shape during baking.
05 -
Preheat oven to 350°F (175°C). Press an indentation in each dough ball center using your thumb or the back of a rounded teaspoon. Bake 12-14 minutes until edges turn light golden.
06 -
Allow cookies to cool on the baking sheet for 5 minutes, then transfer to a wire rack to cool completely before frosting.
07 -
Beat powdered sugar, whole milk, softened butter, and vanilla extract until smooth and creamy. Incrementally add green food coloring gel until a vibrant green hue is achieved.
08 -
Spoon or pipe green frosting into each cookie indentation. Press a red heart sprinkle gently into the center while frosting is still wet.