Add cranberries, strawberries, both sugars, and spices to the crockpot. Stir to combine.
Cover and cook on high for four hours, stirring once halfway through.
Blend the hot mixture with an immersion blender or in batches with a countertop blender. Pulse just two to three times for a jam-like texture.
Ladle hot jam into clean jars. Wipe rims and secure lids lightly. Cool at room temperature.
Refrigerate overnight before using.
