Fudgy chewy chocolate cookies with roasted hazelnuts and milk chocolate chunks. If you love Nutella, then these are for you! They are a chocolate-hazelnut dream come true!
Make the cookie dough. Combine soft butter, both types of sugars and vanilla in a large bowl and beat together using an electric hand mixer or a wide spatula until smooth and slightly fluffy. It will look more like wet sand instead of a fluffy aerated mixture and that's what makes these cookies fudgy. It will take 1-2 minutes if using a mixer.
Add the egg and mix it in until well incorporated.
Combine flour, cocoa powder, baking soda, espresso powder and salt in a medium bowl and whisk to blend evenly. If your cocoa powder is lumpy, sift it in. Add flour mixture to the butter mixture and fold it in until just incorporated. Add the milk chocolate chunks and chopped hazelnuts and fold them in.
Cover bowl and refrigerate the dough for 1-2 hours.
Preheat your oven to 350°F and line two large baking sheets with parchment paper.
Scoop up about 2 tablespoon portions of cookie dough and roll into 16-18 balls and place onto baking sheets spacing them at least 2 inches apart. Flatten dough balls slightly using the palm of your hand or the bottom of a measuring cup. Press extra chocolate chunks and hazelnuts on top and bake for 9-11 minutes until set around the edges and slightly soft in the middle. Do not over-bake these - they will continue to set on the hot tray.