In a mixing bowl, combine glutinous rice flour and sugar.
Add water gradually, mixing until well combined and smooth.
Transfer the mixture to a microwave-safe bowl.
Cover with plastic wrap and microwave for 1 minute.
Stir the mixture, then cover again and microwave for another minute.
Repeat this process for a total of 3 minutes, stirring in between.
Once cooked, let it cool slightly before handling.
Dust a clean surface with cornstarch to prevent sticking.
Transfer the mochi dough onto the surface and flatten it with your hands.
Cut into equal pieces and fill with your choice of filling.
Shape the mochi into round balls, ensuring the fillings are sealed.
Dust with more cornstarch to prevent sticking.