Set aside 1 cup of the milk and dilute the rice flour and corn starch in it. Stir until homogeneous.
Heat the rest of the milk with the sugar. Add the flour and starch in a thin trickle. Stir nonstop until the cream thickens. Let it cool briefly and add the softened butter. Beat with a mixer until the butter softens.
Smear the bottom of a small oven dish with butter. Sprinkle it with powdered sugar and caramelize it by putting the oven dish on the stove.
Let the caramel cool. Pour the cream into the oven dish and let it cool. Return the oven dish to the stove and leave on low heat for 3-4 min. until bubbles begin to form.
Take the oven dish off the stove and let it cool. Put it in the fridge for at least 2 hours to set.
Pour the prepared dessert into a suitable plate and sprinkle with cinnamon.
Before serving, cut it into slices.