- Bring half and half and whipping cream to a simmer over medium-low heat in a medium-heavy saucepan.
- In a separate, medium size bowl, whisk egg yolks and sugar together.
- When cream is heated, whisk hot cream into egg yolk mixture in a slow, steady drizzle. Return mixture to saucepan and return to stove. Stir continuously over medium-low heat until mixture thickens and coats the back of a spoon. Do not boil.
- Remove from heat and stir in Black Raspberry Jam or Sour Cherry Jam until melted.
- Cover with plastic wrap, setting the wrap directly onto the custard and chill. Freeze in an ice cream maker according to manufacturer's directions.