Preheat oven to 375 degrees. Line baking sheets with parchment paper.
Combine oats, hazelnuts, flour, light brown sugar, melted butter, egg, vanilla and salt in a large bowl.
Place 1 tbsp cookie dough on parchment lined baking sheet. Give cookies extra space, as they more than double in size. I placed 4 on each baking sheet. (If you place too close together, they will spread out and all melt together)
Bake at 375 degrees for 7-10 minutes. Make sure to check frequently. You want the sugars to create a nice golden, caramelized edge that will be firm enough to remove from baking sheet, but not crisp.
When cool, dip first in melted chocolate espresso, then in hazelnuts. Place on parchment paper to set.