Preheat oven to 300F. Slice bagels in half and cut into 1/2" cubes. Spray sheet pan with olive oil spray and place cubed bagel pieces on pan in a single layer. Spray bagel pieces with olive oil spray. Optional: Sprinkle with salt.
Bake for 15-25 minutes, flipping half way, until evenly toasted. Remove from oven and cool. Can store in an airtight container.