In a bowl, combine the strawberry jam and ½ cup of the heavy cream. Mix until well blended. In a blender, whip the peanut butter, vanilla extract, sugar, milk, and remaining heavy cream until fluffy, then fold into the jam-cream mixture.
Chill the mixture for at least 1 hour. Pour into an ice cream maker and churn. Mix for about 25-30 minutes or according to the manufacturer's directions. Transfer the ice cream to a tightly sealed container and freeze until ready to serve. (Store-bought ice cream containers will work well for this.)