Wipe the raspberries to remove any dirt or debris. then mix with the lemon juice, lemon zest, and the vanilla bean. Add to a saucepan and bring to a boil. Mix in the jam sugar, stir to combine, and cook the mixture for 1-3 minutes. Add the raspberry liqueur, and stir until combined. Fill the prepared jars to the brim with the jam and seal tightly. Turn upside down to cool for 10 minutes. Turn right side up and cool completely.
If you'd like, you can substitute peach puree for 1/3 of the raspberries. The combination goes very well together.