Preheat the oven to 350*F. Spray a sheet pan evenly with cooking spray, or line it with parchment paper.
In a large bowl, stir together the oats, vegetable oil, honey, coconut, and salt until evenly coated. Spread the granola evenly on a sheet pan, taking care that the coconut is evenly distributed on the pan.
Bake for 10-12 minutes.
Remove the pan from the oven and stir the granola with a flat-edged or wooden spoon.
Bake another 10-12 minutes more, until the granola has turned a golden brown.
Remove the pan from the oven and add the mango, stirring to incorporate evenly. Let cool.
Using a wooden spoon, break up the cooled granola. Store in a cool, dark place in a tightly covered container for up to 4 weeks.