Stir together first 5 ingredients in a shallow dish. Stir in butter; set aside.
Combine goat cheese, pepper, and salt in a small bowl.
Cut tomatoes in half horizontally; trim a small amount from rounded edges, if necessary, so halves will stand upright. Remove seeds and pulp. Spoon about 2 teaspoons goat cheese mixture into each half.
Dip tomato halves, upside down, in breadcrumb mixture, coating generously. Place, right side up, on an ungreased baking sheet.
Bake at 400° for 15 to 18 minutes or until lightly browned. Transfer tomatoes to serving platter. Drizzle with pesto.
*Panko--large coarse breadcrumbs typically used in Japanese cooking--can be found at Asian or international markets. Toasted fresh breadcrumbs can substitute.