Preheat oven to 350 °F (177 °C). Line baking sheets with parchment paper or silicone baking mats.
In the bowl of a stand mixer fitted with the paddle attachment, cream together butter and sugars for 2 minutes until light and fluffy. Then add in the eggs, beating well after each egg, then finally the vanilla extract and beat for 2 more minutes.
1/4 cup unsalted butter, 3/4 cup granulated sugar, 3/4 cup dark brown sugar, 2 eggs, 1/2 teaspoon vanilla extract
Add the peanut butter and baking soda and mix until well incorporated. Then add the oats, hazelnuts, and chocolate chips. If it seems like your mixer is straining a bit, you can stop it and do it by hand, but it should be ok with the mixer.
9 ounce chunky peanut butter, 3/4 teaspoon baking soda, 3 cups old fashioned oats, 1 cup chopped hazelnuts, 1 cup mini chocolate chips
Using a large cookie scoop, drop dough onto lined baking sheets and gently press down to flatten the tops with a fork.
Bake for 13-15 minutes depending on how large your cookies are. You're looking for the edges to be slightly brown and crisp.
Let cool on baking sheet for 5 minutes then move to a wire cooling rack to cool completely.