In a bowl, add melted butter, brown sugar and castor sugar. Whisk everything until well combined.
Add milk and vanilla extract in it and mix again.
Now add in the dry ingredients flour, cornflour and baking soda and combine to form a dough.
Fold in the chopped dark chocolate and pistachios in the dough.
For the pistachio paste, in a blender jar add pistachios, white chocolate and condensed milk. Blend everything together until you achieve a smooth pistachio paste. Measure 1 tbsp and freeze them for about 10-15 minutes or until set.
Scoop out even sized portions of cookie dough and place pistachio paste ball inside the cookie dough.
Add more dark chocolate chips and pistachios on top. Refrigerate the cookies for atleast 10-12 minutes.
Bake them at 180 for 12-15 minutes or until the edges are brown.
Recipe by Bake with Shivesh at https://bakewithshivesh.com/chocolate-pistachio-cookies/