01 -
Beat the softened unsalted butter and granulated sugar together in a large bowl until light and fluffy, about 2-3 minutes for optimal aeration.
02 -
Mix in the egg yolk and vanilla extract until fully incorporated and the batter is smooth and homogeneous.
03 -
Gradually add the all-purpose flour and salt, mixing just until combined to preserve a tender texture without overworking the dough.
04 -
Roll dough into 1-inch balls, place spaced 2 inches apart on a parchment-lined baking sheet, and chill in the refrigerator for 30 minutes to help maintain shape.
05 -
Preheat oven to 350°F. Use your thumb or the back of a rounded teaspoon to press an indentation in each dough ball. Bake for 12-14 minutes until edges just begin to turn golden.
06 -
Allow cookies to cool on the baking sheet for 5 minutes before transferring to a wire rack to cool completely.
07 -
Beat powdered sugar, milk, softened butter, and vanilla extract until smooth and creamy. Add green gel food coloring gradually until a vivid green shade is achieved.
08 -
Spoon or pipe green frosting into each cookie indentation and press a red heart sprinkle into the center while frosting is still wet.