In a medium bowl, whisk together flour and salt.

In a large bowl, cream together butter, sugar, and vanilla until fluffy.

Add eggs and beat until well combined.

Gradually add dry ingredients until well combined.

Transfer the dough to a smaller bowl and cover with plastic wrap.

Chill for at least 1 hour or overnight.

While the dough is chilling, crush hard candies by separating the colors and adding them to a resealable bag.

Beat the candies with a rolling pin or flat end of a meat mallet until finely crushed.

Line baking sheets with parchment paper or silicone mats.

Remove dough from the refrigerator and work with about ⅓ at a time.

Cover the work area with a dusting of flour.

Roll dough to about ¼ thick.

Cut dough with cookie cutters of your choice.

Transfer the cut dough to the prepared baking sheet.

Cut the center of the cookie dough with a smaller cookie cutter.

Repeat with the remaining dough.

Fill the centers with crushed candies, being careful not to overfill them.

Chill the filled cookies in the refrigerator until firm, about 20-30 minutes.

Move the oven rack to the middle position.

Preheat oven to 350 degrees F.

Bake for 10-12 minutes or until lightly golden brown, rotating the baking sheets halfway through.

Remove the baking sheets from the oven and cool on a wire rack for 10 minutes.

Transfer the cookies onto the wire rack to cool completely, about 50 more minutes.