In a medium bowl, whisk the flour, salt, baking soda and baking powder together.
In the bowl of the stand mixer fitted with a paddle attachment, beat the butter on medium speed for 1 minute, until smooth. Add the sugar and brown sugar and beat for 2 minutes, until well blended. Beat in the vanilla.
Add in the eggs, one at a time, beating for minute after each egg goes in. Reduce the speed to low and add in the flour mixture in 4-5 additions, mixing only until each addition is just incorporated (about 5 seconds for each addition - don't over-mix!)
Still on low speed, mix in the chocolate chips and the hazelnut (or almond) flour. Refrigerate dough for 2 hours or up to 3 days. If you are planning to freeze a portion - you can scoop out 1 1/2-inch rounds of dough to freeze.
Preheat oven to 350F with rack centered. Line two baking sheets with parchment paper. Scoop out 1 1/2" rounds of dough onto baking sheet, about 2-inches apart.
Bake the cookies one sheet at a time for 8 minutes, and then, using a spatula, gently press each mound down just a little; rotate the baking sheet when returning to oven. Bake for another 7 minutes, or so, until the cookies are pale brown. They'll still be slightly soft in the center, but that's fine- they'll firm up as they cool. Transfer to rack to cool. Repeat with remainder of dough, always using a cool baking sheet.