Preheat oven 375F/190C.

In a small bowl, combine the sugar and cinnamon and mix well. Set aside.

In a small pot or saucepan, combine the milk and butter and heat over low-medium heat. Once butter has just melted, remove from heat. Do not allow the mixture to boil.

In a mixing bowl, whisk together the glutinous rice flour, sugar, baking powder, and salt.

Add the hot milk-butter mixture to the dry ingredients in the mixing bowl and mix until the fine glutinous rice flour has been incorporated. Texture will be coarse and pebble-like.

Add the beaten egg to the bowl and mix well until mixture comes together into a dough.

Lay a sheet of parchment paper on your countertop and lightly dust it with glutinous rice flour. (See Recipe Notes below.)

Transfer the mochi dough to the floured parchment and use your hands to press the dough into a cohesive mass. Shape the dough into a brick-like block.

Dust a rolling pin with glutinous rice flour and roll the dough out into a rectangle, roughly 10" x 6".

Brush the dough with the melted butter on the dough (you will not use most of the melted butter).

Divide the remaining melted butter among 6 muffin cups of your muffin tin, brushing the melted butter up the sides of each cup.

Sprinkle the cinnamon sugar mixture over the buttered surface of the dough, making sure to go to the edges and to use the entire sugar cinnamon mixture.

From the short side of the dough, start to roll the dough. You will end up with a fat roll at the end that is about 6" in length.

Using knife dusted with glutinous rice flour, or a thread, cut the dough into 6 even pieces.

Transfer each roll to a greased muffin cup, gently pressing down to make sure it is touching the bottom.

Bake for 25 minutes until golden brown around the edges and surface is crackled.

Remove pan from oven and let the rolls sit for 5 minutes before transferring them to a cooling rack.

In a bowl, whisk together the icing sugar and milk (or water) so no lumps appear. Adjust the amount of icing sugar or milk until you get a syrupy consistency similar to maple syrup.

Drizzle glaze over mochi cinnamon rolls.

Mochi cinnamon rolls are best eaten the same day.