Make ice cream balls by scooping ice cream into a mold and placing them in the freezer to firm up.
In a bowl, weigh and mix water, mochiko flour, and granulated sugar until the mixture is smooth.
Cook the mixture in a frying pan over medium-low heat, stirring constantly for about 2 minutes, then let it cool.
On a cornstarch-dusted surface, roll out the mochi dough to a ¼ inch thickness and cut it into circles.
Place each ice cream ball onto a mochi circle, then carefully pull up the edges of the dough to seal around the ice cream.
Freeze the sealed mochi balls until firm. You can store them wrapped in plastic in the freezer for up to 3 months.
Notes
Use a cookie cutter for even sizes, work quickly to prevent melting, dust surfaces with cornstarch to prevent stickiness, and customize flavors to your liking.