Mix the flour and water in a glass, or heat proof bowl, and mix it well. If it's too dry, add some more water, 1 Tbsp at a time.
For about 20 minutes, steam the dough in a steamer.
Take the steamed Mochi and transfer it into a pot. Cook on medium or medium low heat with 1/3 of the sugar. (2/3 of a cup) Once sugar os dissolved, add another 1/3 of sugar, and mix it well. Continue to add the sugar until it's all dissolved. Take time to melt the sugar, but be really careful not to burn it.
From the pot, take the hot mochi and place it onto a sheet pan, dusted with cornstarch, and shape as you like.
The Anko or Ice Cream can be used with the Mochi here. It gives it some extra flavor when you wrap the Mochi dough around this, even though the Mochi can be eaten by itself.