This was a favourite with my son when he was in primary school. I would make a batch every Sunday so that I could pack a couple in his lunchbox or recess.

Ingredients
All-purpose flour 1 1/4 cup
White sugar 1/2 cup
Brown sugar 3/4 cup
Egg 1
Baking soda 1/2 tsp
Salt 1 tsp
Unsalted butter 1/2 cup, melted
Chocolate chips 1/2 cup
Dark chocolate 1 cup, roughly chopped
Method
Sift the flour, baking soda and salt.
Mix the sugars and butter in a bowl.
Add the egg and beat with a electric whisk till the mixture is a light brown and fluffy.
Fold in the flour and both kinds of chocolate.
Leave the dough in the refrigerator for 45 minutes.
Scoop out small balls of the dough and arrange on a greased tray. Leave enough space for the dough to spread.
Bake in a 180 degree C oven for 12-15 minutes. Check after 10 minutes and take the cookies out when they turn a light brown.
Cool on a wire rack. Store in an airtight container when completely cool.

Chec