Raspberry jam is a big seller in our home and even though it is more expensive to make than strawberry jam (because the berries are more expensive), we still make our own raspberry freezer jam every year.
The method is exactly the same as I demonstrated in the strawberry freezer jam video EXCEPT that it requires 2 cups of crushed berries, rather than 1-3/4 cups. The recipe in the CERTO package suggests that half of the raspberry pulp can be sieved to remove some of the seeds if desired, but I personally have never done this step and have no problem with the "seedy" results. You still mix the crushed fruit and sugar and let it stand for 10 minutes, then add the CERTO liquid pectin and lemon juice and mix for 3 minutes. Ladle into containers, let sit 24 hours, and then freeze - easy!
Raspberry freezer jam is so fresh and luscious that I never bother to make cooked raspberry jam. You can even use unsweetened frozen fruit that has been thawed in the fridge to make this simple jam, so if you are too busy in the summer throw some fresh berries in the freezer now and you can make some jam later.*
* One tip: I am quite bug phobic and, seriously, split open and inspect every single raspberry before I crush it...the little space left where the stem used to be is the perfect home for little beer beetles and it's just not nice to have crunchy beetles in your jam! Ye be warned!