Sprinkle gelatin over 1/3 cup almond milk in a small bowl; let stand 4 minutes.
Combine 1 1/3 cups of almond milk, half-and-half, sugar, and half of the vanilla bean in a medium saucepan; bring to a simmer over medium heat (do not boil). Remove from heat. Add gelatin mixture, stirring until the gelatin dissolves. Remove vanilla bean. Pour mixture evenly into 6 (6-ounce) custard cups coated with cooking spray. Cover and chill 8 hours or overnight.
Combine remaining half of the vanilla bean and nectar in a small saucepan; bring to a boil. Reduce heat to medium, and cook until reduced to 1 cup (about 15 minutes). Remove from heat; stir in lime juice. Cover and chill.
Loosen edges of custards with a knife or rubber spatula. Place a dessert plate, upside down, on top of each cup; invert onto plates. Spoon the sauce around custards. Garnish with fresh raspberries, if desired.