To make cookies that are thin and crispy, we picked our ingredients carefully: cake flour, melted butter, egg yolk and a combination of brown and white sugar. Cake flour contains less protein than all-purpose flour does, so it forms less gluten when it’s mixed into a dough. Since gluten gives baked goods their structure, a cookie with less gluten will spread out more in the oven. Using melted butter makes for a softer, moister dough that spreads out as it bakes. Like gluten, egg proteins help give baked goods structure. Skipping the protein-packed egg white keeps our cookies thin and crispy. The brown sugar adds molasses-y flavor while the white sugar holds on to less moisture to help with crispness. Last but not least: Pressing these cookies before they go into the oven encourages them to spread out evenly for optimal crispiness! Crispy Chocolate Chip Cookies Makes 12 cookies Recipe …