It's made from the burnt crust stuck to the bottom of the rice pot — Malagasy cooks pour boiling water over that scorched layer instead of scraping it out and tossing it.
After rice is cooked and served, the caramelized crust left in the pot is steeped in boiling water to make ranon'apango, a lightly smoky, tea-colored drink also called ranovola ('golden water'). It's poured free alongside nearly every home and street meal in Madagascar, from breakfast mofo gasy to dinner.