Make the panna cotta: In a bowl, sprinkle gelatin over ⅓ cup milk; let sit for 10 minutes. Bring remaining milk along with the cream, basil, and ¾ cup sugar to a boil in a 4-qt. saucepan; stir until sugar dissolves. Transfer to a blender, add gelatin mixture, and puree until smooth; pour into eight 4-oz. ramekins. Chill until firm, 3–4 hours.
Make the sorbet: Bring remaining sugar, tomatoes, salt, and ½ cup water to a boil in a 4-qt. saucepan over medium-high heat; reduce heat to medium-low and cook, stirring, until tomatoes break down, 12–15 minutes. Puree in a blender; strain and chill. Process in an ice cream maker according to manufacturer's instructions. Freeze until firm.
Make the candied pine nuts: Heat sugar and 1 tbsp. water in a 1-qt. saucepan over medium heat, and cook, swirling, until bubbling; add pine nuts and coat. Spread nuts on a sheet of foil; cool. Break apart into bite-size pieces; set aside. To serve, briefly dip the bottom of each ramekin in a bowl of hot tap water, invert onto a serving plate; top with nuts. Serve with a scoop of tomato sorbet topped with cherry tomatoes.