In a large bowl, combine all of the ingredients in order. Once fully incorporated, add a pinch of flake salt. Cover the bowl with plastic wrap and let rest for 30 minutes.
Preheat the oven to 275º. Remove the plastic wrap and spread the mixture evenly onto a parchment-lined sheet pan. Sprinkle the top lightly with more flake salt and bake until the granola bars have completely hardened, 1 hour and 45 minutes to 2 hours.
Transfer the sheet to a cutting board and remove the parchment paper. Cut the granola bars into rectangles 4 inches in length and 1½ inches in width. Allow the bars to completely cool before serving. Store in an airtight sealed container for up to 1 week.