Preheat the oven to 350°F with a rack in the center position. Using a sharp knife, make 4 parallel cuts on one flat side of the cheese, cutting just through the rind but not much deeper. Turn the cheese 90° degrees and make 4 more parallel cuts.
Cut a round of parchment a little larger than the brie. Place the parchment in the bottom of a small baking sheet or oven-safe skillet. Put the brie on the parchment, scored side up, on top.
Spread the jam/preserves on top of the brie and season with pepper. In a small bowl, combine the crushed crackers and olive oil and stir until the crumbs are coated in oil. Sprinkle the cracker crumbs on top of the jam.
Transfer the brie to the oven and bake for about 10-15 minutes (keeping a close eye that your Brie doesn’t completely melt like mine lol) until the cheese is warm and the cracker crumbs are lightly toasted.
Transfer the cheese to a serving plate. Sprinkle the cheese with chopped rosemary and flaky salt and serve immediately with more crackers. That’s it!