STEP 1/5
Cream the butter in a bowl and mix with sugar powder and salt.
STEP 2/5
Add egg yolk and vanilla extract. (If you don't have vanilla oil, you can skip it.)
STEP 3/5
Add the powder and make the dough into a lump, remove 60g of dough, put it in a bowl, and knead with cocoa powder and baking powder. Little by little, mix the chocolate dough into the main dough.
STEP 4/5
Make the marble-shaped dough round and long, wrap it in paper foil, hold both ends, and mold it into a circle. Let it harden in the freezer for at least 4-5 hours.
STEP 5/5
Remove the dough from the freezer and cut it into 1cm thick pieces when it's ready. Place Teflon sheet or parchment paper in oven pan, place dough, and bake in preheated oven at 180 degrees for 10-12 minutes.
Please prepare it in advance.
Remove eggs and butter at room temperature in advance.
-Please sift the powder in advance.