Mix brown sugar, white sugar, and melted butter in a bowl. (I use homemade brown sugar ~ equal ratios to store bought)

Add egg yolk and vanilla extract, and mix until smooth. (No mixer needed for this recipe)

Sift in flour, baking soda, corn starch, and salt. Stir until just combined.

Fold in chocolate chips.

Place the bowl with dough in the freezer for 10–20 minutes.

Preheat oven to 350°F. Shape dough into a ball and place on a baking sheet.

Bake for 13-18 minutes until edges are golden.

Cool on a rack before serving. (Let rest on pan 5 minutes before transferring to rack):) Enjoy