Wipe the raspberries and mix with the lemon juice and the lemon zest. Bring the mixture to a boil, add the jam sugar, and stir until combined. Cook for 3-4 minutes until thickened, then mix in the raspberry brandy. Fill the prepared jars to the brim with the hot jar.
Seal the jars tightly, then turn upside down to cool for 10 minutes. Turn right side up and cool completely.