In a medium bowl, puree the raspberries with an immersion blender.
Pour the pureed raspberries into a medium sauce pan.
Using a sieve, pour the mixture through and press lightly to separate the juices of the berries from the skin and seeds into a bowl.
Discard the seeds and flesh (put them in your composite pile if you have one).
Add sugar to the juice that has the seeds and skin/flesh removed.
Return to the pan on a medium to high temperature burner on the stove.
Add raspberry jam/preserves.
Bring to a boil and stir for about 3 minutes.
Refrigerate until ready to use.
Serve with your favorite flavor of ice cream or pound cake.