Use a rubber spatula to scoop out the icing from the container and into a large mixing bowl. Then add two cups of the powdered sugar to the bowl and blend the ingredients together. You can start mixing using a spoon however, it will be easier for you to use your hands to work the dough into a good consistency.
Add the sprinkles and any additional powdered sugar as needed to help get the play dough to a workable consistency or if it seems to be too sticky to work with. Once you are able to form a ball, the play dough is ready to use.
If you are adding the optional powdered mix, you can do that in the first step and adjust the powdered sugar as needed.
*Note: You can add more sprinkles as desired as the kids are playing with the dough for sensory play. Kids can watch how the colors blend in with the dough and change.
Store the dough in an air tight container. It should keep for a few days at room temperature.