Preheat oven to 180 degree C. Line a 20 cm square baking pan with parchment paper and butter it really well. Set aside.

Take butter in a sauce pan and melt it lightly, add in white chocolate into the melted butter and mix well till it is melted. Set aside till it cools.

Now take flour, salt, baking powder in a sifter and sieve well. Set aside.

Take eggs, sugar, vanilla in a large bowl and use a beater to whip this till fluffy and pale.

Now pour in the chocolate mix and whip it up.

Now add in the flour mix and fold gently,

Finally add in the semi sweet chocolate chips and fold gently.

Pour this into the baking pan and bake for 25 to 30 mins until the toothpick inserted comes clean.

Remove it from oven and let it cool completely. Cut into bars and serve