Step-by-Step Instructions

• Preheat your oven to 350°F (175°C) and line two baking sheets with parchment paper.
• In a mixing bowl, cream together butter and sugar until light and fluffy, about 2-3 minutes.
• Beat in the egg and vanilla extract until well combined and smooth.
• Whisk together flour, baking powder, and salt in a separate bowl, then gradually add to the wet mixture until just incorporated.
• Divide dough into two portions, mixing cocoa powder into one for the chocolate layer.
• Roll out both doughs into rectangles of about ¼ inch thick between parchment paper.
• Layer the chocolate dough on top of the plain dough, aligning edges.
• Roll the dough into a tight log and wrap in plastic wrap. Chill in the refrigerator for at least 30 minutes.
• Slice the chilled log into ¼ inch thick rounds.
• Arrange the cookie rounds on the prepared baking sheets and add toppings if desired.
• Bake for 10-12 minutes or until the edges are lightly golden. Cool on the sheets for a few minutes before transferring to a wire rack.