In a bowl, sift and add together the all purpose flour, baking powder, and salt. Whisk together and keep aside.
Add unsalted butter to a mixing bowl. Beat using an electric beater or whisk well until soft. Make sure the butter added is at room temperature.
Add sugar and vanilla extract to the butter. Cream the butter and sugar until light and fluffy.
Gradually add the dry ingredients to the wet ingredients, mixing until a soft dough forms. Divide the dough into two halves.
Mix sifted cocoa powder and to one half of the dough. Roll both the doughs into balls and keep them ready.
Make small size balls from both the vanilla and chocolate dough.
Take vanilla ball , chocolate ball and alternate them. Bring them together as shown in the picture. (look for the step by step pictures given above the recipe card)
Gently flatten them so that it looks like a marbled ball. Preheat the oven to 350°F (180°C) and line a baking sheet with parchment paper or silicone mat.
Place the cookie dough on the prepared baking sheet.
Bake at 350°F (180°C) for 12-15 minutes, or until the edges and bottom are lightly golden.
Allow cookies to cool on the baking sheet for 5 minutes. Transfer to a wire rack to cool completely.
Initially the cookies may seem soft. Once it completely cools down, it firms up. Enjoy with a cup oof milk/tea or coffee. store these eggless marble cookies in an airtight container.