In a large bowl, beat the butter and sugar together until light and fluffy.

Add the egg yolk and mix until fully combined.

In another bowl, whisk together the flour and salt.

Add the dry ingredients to the butter mixture and mix until a soft dough forms.

Divide the dough into two equal portions:

●      Tint one half red

●      Tint the other half blue

Mix each portion until the color is fully incorporated.

Roll each colored dough into small balls (about 1 tbsp each).

Roll each ball generously in powdered sugar.

Flatten slightly into thick discs (“little pucks”).

Place the shaped cookies on a tray and freeze completely — at least 1 hour or until solid.

Freezing helps create the signature deep crinkle effect and prevents spreading.

Preheat the oven to 350°F (180°C).

Place the frozen cookie discs on a parchment-lined baking sheet.

Bake for 12–15 minutes, or until the cookies puff and crackle.

If the powdered sugar starts to brown, remove the cookies immediately.

Let cool completely on the tray.

Once cooled, the cookies will have bright red and blue crinkles with a soft center.