Preheat the oven to 350°F with a rack in the center.

Generously grease an 8-inch (20-cm) baking pan and line the bottom with parchment paper. (Note: This cake sticks to the bottom because it's made with glutinous rice flour and not a lot of oil, unlike butter mochi, which is more generous with butter, but it's still sticky, oh the irony!).

The ideal way to whip up this batter is to whip everything in a blender, adding all the wet ingredients to the bottom first. Blend until you get a smooth, homogenous, runny but thick batter. Of course, you could also mix the batter by hand or with a stand mixer fitted with the paddle attachment.

Pour all of the batter into the pan and bake for at least 60 minutes, until the top has browned and an inserted toothpick or bamboo skewer comes out clean. A little bit of sticky residue is OK.

You can remove the cake from the oven and allow it to set inside the hot pan.

Flip the cooled cake out of the pan. Cut a ripe mango into thin slices and form into a mango rose or flower and decorate the top of the cake as you please. Dust with the optional confectioners' sugar or butterfly pea flower powder, or both. Add coconut shreds if you’d like, slice, serve, and enjoy!