To prepare panna cotta, sprinkle gelatin over 1 cup milk; let stand 1 minute.
Combine remaining 1 3/4 cups milk, 1/4 cup sugar, rind, and vanilla bean in a medium saucepan over medium heat; bring to a simmer. Cook 5 minutes, stirring occasionally. Add gelatin mixture to milk mixture; stir until gelatin is completely dissolved. Discard rind and vanilla bean. Cool.
Divide the mixture evenly among 8 (6-ounce) custard cups coated with cooking spray. Cover and chill at least 4 hours or overnight.
To prepare sauce, press raspberries through a sieve over a bowl; discard seeds. Combine 1 tablespoon sugar and cornstarch in a saucepan; stir until blended. Stir in raspberries and jelly; bring to a boil. Cook 1 minute, stirring constantly. Cool.
Loosen edges of custards with a knife or rubber spatula. Place a dessert plate, upside down, on top of each custard cup; invert custard onto each of 8 plates. Spoon 2 tablespoons sauce around each serving. Garnish with mint sprigs, if desired.