Cream the butter and sugar with beater and then add eggs one at a time.
Then beat on high speed until smooth and fluffy.
Add yogurt and milk and beat well.
Sift flour with baking soda, baking powder, salt and add gradually mix in with the previously prepared mixture using a spoon.
Add few drops of vanilla essence and then divide this batter in 2 bowls.
Mix melted chocolate in one bowl.
Grease a round 8 inches baking pan and line with baking paper and now assemble the two layer cake carefully.
Add one tablespoon vanilla batter in the center of the pan then in the middle add the chocolate batter then the vanilla then choco and repeat until the all two mixtures are in the pan.
Give it a minute for setting.
Then bake it for 30 minutes on 180°C.
After baking, let it cool for a few minutes and pan out.
Cut in square pieces or as desired and serve.
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