Heat oven to 375° F.
Place the buns on a baking sheet, cut-side up. Bake until crisp and lightly browned, about 10 minutes; let cool.
Transfer to a food processor or blender. Add 1 teaspoon salt and ¼ teaspoon pepper. Pulse until finely ground. (You can store the crumbs in a resealable plastic bag in the refrigerator for up to 5 days or in the freezer for up to 3 months.)