Preheat the oven to 350°F (175°C) and line a baking sheet with parchment paper.

Melt 1/2 cup of butter in a mixing bowl. Combine with 1 cup of sugar, 2 egg yolks, and 1 teaspoon of vanilla. Mix until smooth.

Add a few drops of green gel food coloring. Then, sprinkle in 2 cups of flour, 1 teaspoon of baking soda, and 1/4 teaspoon of salt. Fold the dry ingredients into the wet mixture until just combined.

Form about 12 balls of dough (1.5 tablespoons each) and roll in granulated sugar.

Place dough balls on the baking sheet with 2 inches between them. Bake for 10-11 minutes until puffed and lightly golden.

Immediately press a red heart sprinkle into each cookie while still warm. Allow to rest for 2 minutes before transferring to a wire rack.

Transfer to a wire rack to cool completely before enjoying.