Whisk 4 ounces cream, maple syrup, pumpkin puree, pumpkin pie spice, and vanilla extract together in a microwave-safe bowl. Heat pumpkin mixture in the microwave in 30-second intervals, stirring between intervals, until heated through and completely blended, 1 to 3 minutes.
Pour sweetened condensed milk, remaining 10 ounces cream, and pumpkin mixture into a container, cover the container with a lid, and shake until completely mixed. Store in the refrigerator.
