Step 1

Scoop the ice cream into seven 2-inch-wide balls, and place each ball in a cupcake liner in an airtight container. Freeze for at least 2 hours, or overnight.

Step 2

After the ice cream has been frozen for at least 2 hours, prepare the mochi dough.

Step 3

Whisk together the mochiko and sugar in a microwaveable bowl. Add the water and mix until the water is fully incorporated. You shouldn't see any lumps, and the mixture should look smooth, like pancake batter.

Step 4

Microwave, uncovered, on high for 2 minutes.

Step 5

Dip a spatula in water and use it to stir the mochi dough. The dough should be sticky, thick, and starting to look glossy. Mix well so that the dough heats evenly and almost all the dough becomes the same color.

Step 6

Microwave the mixture for 2 minutes longer.

Step 7

Remove the mochi mixture from the microwave and stir well with the spatula.

Step 8

Rub a large cutting board with the cornstarch, focusing on the middle section of the board where the cooked mochi dough will be placed. Be sure to use a large cutting board, since the mochi dough will be rolled flat and will need ample space. Transfer the mochi to the center of the board. Let cool for 5 minutes.

Step 9

Generously dust the top of the mochi dough and a rolling pin with cornstarch. Push down on the mochi to flatten it, then roll it to 1/4-inch thickness.

Step 10

Using a 4-inch circular cookei cutter, cut out seven 4-inch circles of dough.

Step 11

Working with one circle at a time, remove a ball of ice cream from the freezer, remove the cupcake liner, and place the ball upside down in the center of the circle.

Step 12

Pull up the dough corners and pinch to seal the seams around the ice cream. Place the mochi seam side down on a fresh cupcake liner, then freeze.

Step 13

The ice cream will start melting almost immediately, so it's important to assemble and freeze each mochi quickly and individually.

Step 14

Once all the mochi ice creams are assembled, freeze them for at least 1 hour.

Step 15

To enjoy the mochi ice cream, let it soften at room temperature for 2 minutes before eating.