Preheat the oven to 160 degrees C (325 degrees F).
Mix Unsalted Butter (1/2 cup) and Caster Sugar (115 gram) until slightly colored and fluffy.
In another bowl beat Egg (1) and Vanilla Essence (1 teaspoon).
Add the egg and vanilla mixture into the butter mixture. Mix well.
Sift All-Purpose Flour (175 gram) over the butter mixture and beat it until fully incorporated.
Add Chocolate Chips (175 gram) and fold in.
Put the batter on a greased baking sheet 2 inches apart leaving space to increase in size while cooking.
Bake for 20 minutes
Let it cool on the tray for 5 to 10 minutes then move them to a wire rack to cool.