Preheat oven to 375°F. Line a sheet pan with parchment paper.
In the bowl of a stand mixer fitted with a paddle attachment or with a hand-held mixer, beat the butter and sugars on medium high speed until light and creamy, about 3-4 minutes. Scrape down the bowl as needed. Add the egg and vanilla.
In a separate bowl, combine the flour, hazelnut flour, baking soda, and salt. Mix until incorporated, mixture may be a little crumbly. Mix in the chocolate chips and chopped hazelnuts.
Drop cookies by the rounded tablespoon onto the prepared sheet pan. Bake until golden brown, about 10-12 minutes. Let cool for a few minutes on the pan, then move to a wire rack to cool completely.
Store cookies in an airtight container at room temperature for up to one week.
NOTES
- Look for hazelnuts (or filberts, as they're also known) in the bulk section of a specialty supermarket. I use Bob's Red Mill hazelnut flour. If you're having trouble locating either near you, buy online.
- If you would like to omit the hazelnut flour, simply leave it out and increase the whole wheat flour to 2 cups (226 grams).
Calories: 258kcal, Carbohydrates: 28g, Protein: 4g, Fat: 15g, Saturated Fat: 8g, Cholesterol: 22mg, Sodium: 71mg, Potassium: 173mg, Fiber: 2g, Sugar: 19g, Vitamin A: 187IU, Vitamin C: 1mg, Calcium: 67mg, Iron: 1mg