Preheat oven to 350 degrees. Spread almonds in a single layer on a rimmed baking sheet, and bake until lightly toasted and fragrant, 7 to 8 minutes.
In a medium bowl, combine tamari and maple syrup. Add almonds, and toss until thoroughly coated. Lightly cover the baking sheet with cooking spray, and spread almonds evenly on sheet.
Roast in oven until deep brown, stirring once, 15 to 17 minutes. Immediately transfer to a clean baking sheet, and spread out almonds, separating so nuts don't touch. Let cool before serving.