For vanilla dough, Beat butter and sugar with vanilla extract till creamy. Add flour gradually mix and make a dough. Wrap in plastic wrap and store in fridge for 30 min.

For chocolate dough, beat butter and sugar till creamy add flour and cocoa powder and mix together makes a dough. Wrap in plastic wrap and store in fridge for 30 min.

When the doughs became chilled. Roll and make three equal size layers on butter paper. Do again this with chocolate dough.

Place three slabs of dough alternating vanilla and chocolate dough, one on top of the other. Gently press the slabs together.

Rearrange the slabs of dough to create two slambs forming 9 small rectangles cross-wise.

Wrap each slab with plastic wrap and place in fridge for another 30 min. Preheat oven at 180° C.

Unwrap the dough and slice it ¼ iches thick slice in cross wise. Bake it in preheated oven fo 12 to 15 min per batch.

Dont touch after baking at that time, cool it completely and then shift to wrire wrack. Serve it when it's completely cool snd crisp. Enjoy with tea or coffee.