In a shallow bowl, combine mochiko glutinous rice flour, water, and sugar. Stir to combine. Cover.
Microwave for 2-3 minutes in 1 minute intervals. Stop and stir the mixture after each minute.
Mochi dough will be translucent when fully cooked.
Divide dough into 6 equal portions.
Use a rolling pin dusted with soy bean powder or cooked glutinous rice flour (koh fun) to roll out and flatten into a round circle.
Let the dough cool a little bit.
Remove a pre-portioned scoop of matcha ice cream and place it in the centre of the mochi dough, and quickly pinch the seams together. Remember to work quickly.
Dust with additional powder and place it right back into the freezer. Repeat with the remainder.
Freeze until solid, about 4-6 hours.
To serve, bring to room temperature for about 15 mins.