First, place the sugar in a large microwave-safe bowl, microwave on high 2 minutes or until the sugar is warm.
Stir in the blackberries. Cover with plastic wrap or wax paper, but fold back one edge so the steam can escape. Microwave on high for 1 1/2 minutes, remove and stir and microwave again for another 1 1/2 minutes or until the sugar dissolves.
Uncover and microwave on high 8-10 minutes more or until the berries are very soft and the liquid reduces and thickens slightly.
Stir in lemon juice. Cool, cover and chill in the refrigerator overnight. The jam will continue to thicken as it chills.
Store in your refrigerator for up to 1 week. Enjoy!
The nutrition label below is for 1 6 oz jar of jam.[nutrition-label]