Preheat oven to 375 degrees F. Line two large baking sheets with parchment paper.
Wash potatoes, leaving skins on. Cut into ¼-inch thick slices, about 3 to 4 inches long. Add cut potatoes to a large bowl.
In a small bowl, mix together salt, chili powder, smoked paprika, garlic powder, onion powder and black pepper.
Add 2 tablespoons olive oil and the spice blend to the potatoes and toss until everything is evenly coated. Layer potatoes onto parchment-lined baking sheets, ensuring they are in a single layer.
Place in pre-heated oven for 20 minutes. Use tongs to flip each fry and return to oven, swapping pans to opposite racks.
Turn heat up to 425 degrees and bake for another 30 to 35 minutes, until fries are crispy. Check midway through and rotate pans, as needed.
For the aioli: Mix all ingredients into a medium bowl and whisk together until creamy. Scoop into a serving bowl and serve on a platter with fries.