Preheat oven to 400° Fahrenheit and adjust oven rack to center of oven if needed. Line large baking sheet with parchment paper. Set aside.
Slice 1 16-ounce baguette into diagonal pieces, each piece no wider than ½ inch maximum. Arrange baguette slices on baking sheet in single layer without overlapping.
Brush tops of baguette slices with high-quality olive oil, then lightly sprinkle kosher salt over baguette slices. Flip slices over and repeat on other side. Set aside.
Add 1 cup marinara sauce to small cast-iron skillet or other small baking dish.
Nestle 1 8-ounce ball fresh burrata in center of marinara, then sprinkle ¼ cup grated fresh parmesan evenly over burrata and marinara.
Place baking sheet and skillet in preheated oven. Bake crostini and burrata 6 to 8 minutes or until edges of crostini are golden and marinara is bubbly.
Carefully remove baking sheet and skillet from oven and set aside. Drizzle 1 tablespoon truffle oil evenly over top of burrata.
Transfer crostini to serving plate or bread basket. Sprinkle sea salt and thinly sliced fresh basil over top of burrata and serve immediately with crostini.
Recipe Notes
Crostini: Number of crostini made from 1 baguette will depend on thickness of slices.
Parmesan: For the best flavor and melt, grate your own fresh parmesan from a block rather than using prepackaged grated parm.