Grill the pineapple over medium-high heat for 2–3 minutes per side. Allow it to cool, then cut into cubes. You can also skip grilling if preferred.
In a medium bowl, combine the pineapple, mango, bell pepper, red onion, cilantro, lime juice, and salt.
Stir well and let the mixture rest for 15 minutes so the flavors blend together.
Preheat the oven to 400°F.
Arrange the baguette slices on a sheet pan and brush each slice with olive oil.
Toast the bread for 10–12 minutes or until crisp and golden. Watch carefully after 7–8 minutes to avoid over-browning.
Spoon the Pineapple Mango Bruschetta mixture onto the toasted bread slices and serve immediately.