01 -
In a large mixing bowl, cream together the softened butter and granulated sugar using a hand mixer or stand mixer until light and fluffy.
02 -
Add the eggs one at a time, mixing well after each addition. Stir in vanilla extract until fully combined.
03 -
In a separate bowl, whisk together the all-purpose flour, salt, and baking powder. Gradually add the dry mixture to the wet ingredients, mixing just until a smooth dough forms.
04 -
Divide the dough evenly into two portions. Leave one half plain for the vanilla layer.
05 -
Mix the unsweetened cocoa powder into the second portion of dough until thoroughly blended, forming the chocolate layer.
06 -
Alternately add spoonfuls of vanilla and chocolate dough onto a prepared baking sheet. Use a toothpick or skewer to swirl the dough, creating a zebra-like marbled effect.
07 -
Preheat oven to 175°C (350°F). Bake the cookies for 10-12 minutes, or until the edges are set. Allow the cookies to cool on the sheet for several minutes before transferring to a wire rack.