In a large pot, mash the raspberries using a potato masher or a fork.

Add sugar and lemon juice to the mashed raspberries and mix well.

Bring the mixture to a boil over medium-high heat, stirring constantly.

Once boiling, stir in the fruit pectin.

Continue boiling for 2-3 minutes, or until the jam starts to thicken.

Remove from heat and let it cool for a few minutes.

Pour the jam into sterilized jars, leaving about 1/4 inch of space at the top.

Seal the jars tightly and let them cool to room temperature.

Store in a cool, dark place.