Preheat oven to 400° F (200°C). Place the baguette slices on a baking sheet and bake for 8 minutes, or until crunchy to your liking.
Pour tomatoes into a 9" x 13" oven-proof baking dish. Add olive oil and stir to coat. Place the block of feta into the middle. Sprinkle with salt and pepper and bake for 30 minutes.
When done, remove the dish from the oven. Add the chopped basil. Stir carefully to combine. Avoid over-stirring. Some bits of feta should remain.
Serve with crostini.
Notes
You can bake this in the air fryer, if you want. Place all the ingredients into an air fryer-safe dish. Set the dish inside the air fryer basket. Cook on 400° F for 15 minutes.