01 -
In a large bowl, blend butter and powdered sugar for 3-5 minutes until creamy. Add egg yolks, vanilla extract, and salt; mix until combined.
02 -
Divide the butter mixture into two equal parts. For the white dough, stir in 1 1/4 cup all-purpose flour. For the chocolate dough, mix in 1 cup all-purpose flour and 1/4 cup cocoa powder.
03 -
Roll 1/4 teaspoon portions of each dough into small balls.
04 -
To create swirls, take 3 balls from each dough and alternate them in a flower shape. Lightly press the balls together, then gently roll into a swirl shape.
05 -
Flatten the swirls slightly and place on a parchment-lined baking sheet. Chill for 15-30 minutes.
06 -
Preheat oven to 325°F (160°C). Bake the cookies for 13-15 minutes or until the edges are golden.