Preparation Steps

• Preheat the oven to 350°F. Line two baking sheets with parchment paper and set aside.
• Put the rolled oats in a blender or food processor and pulse until they form a fine to medium oat flour—stop before they become gummy. Transfer to a medium bowl.
• Whisk the all-purpose flour, oat flour, salt, baking powder, baking soda, and instant espresso powder together in the bowl until evenly distributed; set aside.
• In a stand mixer fitted with the paddle (or using a hand mixer), cream the butter with the granulated and brown sugars on medium speed until the mixture is pale and fluffy, about 3–4 minutes.
• Add the eggs one at a time, mixing until incorporated, then add the vanilla and beat for 20–30 seconds more, scraping the bowl down once.
• With the mixer on low, add the dry ingredient mixture in two additions, mixing just until no dry streaks remain. Avoid overmixing to keep the cookies tender.
• Using a spatula, fold in the chocolate chips, grated chocolate, and the chopped nuts until evenly distributed through the dough.
• Scoop the dough into rounded 2-tablespoon portions onto a baking sheet, spacing them about 2½ inches apart. For thicker cookies, cover the sheet and chill the scooped dough in the refrigerator for 30–45 minutes (this step is optional but recommended).
• Bake one sheet at a time in the preheated oven for 12–14 minutes, rotating the pan halfway through. Cookies are done when edges are golden and centers still look slightly soft.
• Allow the cookies to rest on the baking sheet for 5–6 minutes so they set, then transfer to a wire rack to cool completely.