OMG! WORLD'S BEST DOUBLE CHOCOLATE CHIP COOKIES RECIPE!

INGREDIENTS
200g butter (room temperature)
300g caster sugar
1 large egg
275g self-raising flour
75g cocoa powder
a dash of milk (Optional)
1 large bar of white chocolate
1 large bar of milk chocolate
1 large bar of dark chocolate (Optional)
3 Daim bars (Optional)