Blackberry Buttermilk Syrup (Joycelyn)

1 cup seedless blackberry jam
1 stick butter
3/4 cup sugar
1/2 cup buttermilk
1/2 teaspoon baking soda
1 teaspoon vanilla

Place butter, sugar and buttermilk into a large saucepan over medium heat. Stir and melt until mixture comes to a low boil. Add blackberry jam, blend well and bring to a boil. Remove from heat and add in baking soda and vanilla. Mixture will foam. Pour syrup into a serving dish. Cover to keep warm while preparing pancakes.