The perfect chocolate chip cookie

After long and arduous searching, near-endless taste-testing and adapting, combining recipes and adapting some more, (and then much more taste-testing!) I do believe I've finally stumbled upon....

The Perfect Chocolate Chip Cookie
(yeild: about 48)

Ingredients:

1. ¾ cup room temperature butter
2. 1 cup packed brown sugar
3. ¼ cup white sugar
4. 1 Lg egg
5. 1 Lg egg yolk
6. 2 tsp vanilla
7. 2 cups unsifted all-purpose flour
8. 2 tsp cornstarch
9. 1 tsp baking soda
10. 1 cup 55% cocoa Belgian chocolate chips
11. 1 cup 72% cocoa Swiss chocolate chunks

Method:

1. combine flour, cornstarch, and baking soda and blend with a whisk - set aside
2. cream butter and sugars together with wooden spoon
3. add egg and extra yolk continuing to mix until just absorbed
4. add vanilla continuing to mix until just absorbed
5. add dry ingredients and chocolate, folding until just incorporated
6. drop onto parchment lined pans
7. bake @ 345° for no longer than 10 minutes (cookies will appear undercooked when they come out - they should!)
   

I think they stay chewy past three days, but to be honest they've never lasted that long.