Prepare the simple syrup by combining the powdered monkfruit sweetener and water in a small saucepan. Stir to combine and heat until the sweetener dissolves completely, about 3-4 minutes. Remove from heat and set aside to cool.
Place the frozen pineapple, pineapple juice, coconut cream, rum, and one-quarter cup simple syrup into a blender and blend until smooth.
While the blender is still running, add the ice cubes a few at a time until the desired consistency is reached.
Turn blender off, remove lid, and taste. Add additional simple syrup, if desired, and blend for another 30 seconds to combine.
Pour into glasses and serve immediately garnished with fresh pineapple slices or mini umbrellas.
Notes
makes 2 drinks*You can use fresh or unsweetened canned pineapple that has been frozen, or frozen pineapple chunks.