Remove cores from tomatoes; cut each tomato in half crosswise. Arrange tomatoes in a shallow 1-quart baking dish.
Combine breadcrumbs, butter, and seasonings in a small mixing bowl; mix well. Spread 1 tablespoon of breadcrumb mixture over cut surface of each tomato. Cover with plastic wrap; refrigerate overnight.
Remove plastic wrap, and let tomatoes stand at room temperature 10 minutes. Bake, uncovered, at 350° for 25 minutes or until topping is golden brown. Garnish each tomato half with chopped parsley, if desired, before serving. Serve warm.