Preheat oven to 185 degrees Celsius

Mix in a large bowl using a wooden spoon: 1/2 cup white sugar, 1 cup brown sugar, 85g melted butter

When mixture becomes thicker, add 1 egg and 1 yolk, and 1 tbs vanilla extract. Then set aside.

In another large bowl, mix with a whisk: 2 cups all purpose flour, 1 tsp baking soda, 1 tsp salt

Add dry ingredients in Step 4 to wet ingredients in Step 3, doing so gradually (1/4th of the dry ingredients at a time). Mix with a wooden spoon.

Add chocolate chips to dough. Keep kneading with a wooden spoon and/or your hands.

Optional step: Refrigerate the dough for 2 hours to add chewiness to texture. In this case, preheat the oven later.

Use an ice cream scooper to scoop the dough into small balls. Place 2 inches apart on a metal baking tray. Slightly flatten each into a cookie shape.

Bake at 185 degrees Celsius for 13 minutes. Make sure cookies don't turn brown; a good color is a pale tan (it will darken later). 8-9 mins for smaller cookies.

When done baking, place cookies in a grill rack to cool. For best results, leave in the refridgerator overnight in a sealed container.

Done! Serve with milk or ice cream for extra tastiness.