Crafting the Cookie Dough
Preheat your oven to 350°F (175°C) and line a baking sheet with parchment paper.
In a large bowl, beat butter and sugar until light and fluffy.
Mix in the vanilla extract and egg yolk.
Gradually add flour and salt, stirring until a soft dough forms.
Shaping and Baking
Roll the dough into 1-inch balls and place them 2 inches apart on the baking sheet.
Press your thumb (or the back of a small spoon) into each ball to create an indentation.
Bake for 12-14 minutes, or until the edges turn lightly golden.
Remove from the oven, let cool for 5 minutes, then press the indentations again while still soft. Let the cookies cool completely.
Preparing the Icing
In a small bowl, whisk together powdered sugar, milk, and vanilla extract until smooth.
Divide the icing into separate bowls and tint each with pastel food coloring.
Decorating with a Festive Touch
Spoon the colored icing into each cookie indentation.
While the icing is still wet, place a mini chocolate egg or pastel candy in the center.
Add sprinkles or edible glitter for extra flair.
Allow the icing to set completely before serving or storing.