Pour the tomatoes with the juice from the can into a saucepan over medium heat and heat until warm, about 5 minutes.
Dissolve the raspberry gelatin in the boiling water. Stir the unflavored gelatin into the cold water until dissolved. Add both mixtures to the warmed tomatoes and stir. Pour the tomato mixture into a gelatin mold and refrigerate until congealed, 3 to 4 hours.