Step 1

Combine dry ingredients - In a large mixing bowl, add flour, cornstarch, baking soda, baking powder, and salt. Whisk until uniform.

Step 2

Whisk wet ingredients -In a large mixing bowl, combine butter, brown sugar, granulated sugar, and thick for 30 seconds or until well blended. Add egg, plus yolk and vanilla until thick and blended, then add the discard and whisk until the mixture is smooth.

Step 3

Mix the dough - Fold the dry ingredients into the wet, mixing just until streaks disappear. Stir in chocolate chips just until dispersed. Don’t over-mix. Cover and chill 4–48 hrs (longer = deeper flavor).

Step 4

Scoop - Preheat the oven to 350 °F/175 °C. For larger cookies, scoop 65-70 g balls on a scale (for smaller cookies, scoop 45 g balls) onto parchment-lined light baking sheets, spacing 3 inches apart. With your hands, roll the dough into balls (no need for perfection)

Step 5

Bake one cookie sheet at a time for 12–15 minutes for larger cookies and 10-12 minutes for smaller cookies until rims are golden and centers still look soft, but the center no longer looks like shiny and wet raw cookie dough. Do not over-bake - they will continue setting out of the oven. Repeat with the second baking sheet.

Step 6

Make them beautiful - for a bakery-quality look, immediately out of the oven, push chocolate chips into the tops of the cookies and they will melt as the cookies cool, resulting in gorgeous cookies with an irresistible amount of melty chocolate in every bite.

Step 7

Cool 5 min on the baking sheet, then transfer (parchment & all) to a rack.