📖 Instructions

1. Toasting Hazelnuts: Preheat your oven to 350°F (175°C). Spread the blanched hazelnuts in a single layer on a baking sheet. Toast for 8-10 minutes, stirring halfway through, until they're fragrant and lightly golden. Keep a close eye on them because nuts can burn quickly. Let them cool completely on the baking sheet.
2. Grinding Hazelnuts: Once cool, transfer the toasted hazelnuts to a food processor. Pulse them until they are finely ground, resembling a coarse flour. Be careful not to over-process them, or you'll end up with hazelnut butter. We want texture here!
3. Combine Dry Ingredients: In a medium bowl, whisk together the all-purpose flour, baking soda, and salt. Make sure these are well combined so the leavening is evenly distributed throughout the dough.
4. Cream Wet Ingredients: In a large mixing bowl, using an electric mixer (either a stand mixer with a paddle attachment or a hand mixer), beat the softened unsalted butter, light brown sugar, and granulated sugar together. Beat on medium speed for about 2-3 minutes, until the mixture is light, fluffy, and pale in color. This step is key for a tender cookie.
5. Add Egg and Vanilla: Beat in the large egg until it's fully incorporated, scraping down the sides of the bowl as needed. Then, add the vanilla extract and beat for another 30 seconds until just combined. Don't overmix here.
6. Combine: Gradually add the dry ingredient mixture to the wet ingredients, mixing on low speed until just combined. Stop mixing as soon as no streaks of flour are visible. Overmixing develops too much gluten, which can lead to tough cookies.
7. Fold in Hazelnuts: Gently fold in the finely ground hazelnuts using a rubber spatula. Mix just enough to distribute the nuts evenly throughout the dough.
8. Chill Dough: Cover the bowl with plastic wrap and chill the cookie dough in the refrigerator for at least 30 minutes. This step is super important! Chilling helps the flavors meld, prevents the cookies from spreading too much during baking, and makes the dough easier to handle.
9. Preheat Oven & Prep: While the dough is chilling, preheat your oven to 375°F (190°C). Line two baking sheets with parchment paper or silicone baking mats. This prevents sticking and helps with even baking.
10. Scoop & Bake: Scoop rounded tablespoons of dough onto the prepared baking sheets, leaving about 2 inches between each cookie. You can gently flatten them slightly with your palm if you prefer a flatter cookie, but they'll spread naturally. Don't overcrowd the sheets.
11. Bake the Cookies: Bake for 10-12 minutes, or until the edges are golden brown and the centers are just set. The cookies might look slightly underdone in the middle, but they will continue to set as they cool. Overbaking will result in a dry cookie, and nobody wants that!
12. Cool: Remove the baking sheets from the oven and let the cookies cool on the sheets for 5 minutes. This allows them to firm up before you move them. Then, carefully transfer the cookies to a wire rack to cool completely. Enjoy these warm, nutty delights with a cup of coffee or a glass of milk!