Marble cookies

Vanilla part:

1 cup all purpose flour
1/4 tea spn salt
1/4 cup sugar
4 tbl spn butter
1/2 tea spn vanilla extract
1/2 tea spn baking powder
1/4 cup milk

Method:

Beat together butter and sugar till they are well incorporated. Add vanilla extract, milk and beat again.
Add salt, flour and baking powder. Mix well into a dough.

Chocolate part:

1 cup all purpose flour
1/4 tea spn salt
1/4 sugar
4 tbl spn butter
1/2 tea spn vanilla extract
1/2 tea spn baking powder
1/4 cup milk + 2 tea spns
3 tbl spn cocoa powder

Method:

Beat together butter and sugar till they are well incorporated. Add vanilla extract, 1/4 cup milk and beat again.
Add salt, flour, baking powder and cocoa powder. Mix well into a dough. If required, add remaining milk 1/2 tea spn milk at a time to make a soft pliable dough.

Putting together the cookie:
Knead both the doughs separately. Preheat the oven at 375 F.
Make about 2 inch thick diameter ropes from the dough. Flatten the rope a bit by pressing down the rope a bit. Keep the chocolate flavored rope down and on top of it, keep the vanilla flavored dough. Dip a sharp knife in loose floor(to avoid sticking to knife) and cut the dough into as thin rings as possible (you can shape them into rounds again, but I liked the shape, so left them as they were).
Keep the rings on a greased baking sheet and bake for about 10-13mins.
When they are cooled to room temperature, store in airtight containers.