Cook a standard pot of short-grain steamed rice. Remove the rice, leaving a thin, even layer pressed against the bottom of the pan. Toast it over medium-low heat for 10-15 minutes.
Meanwhile, brew a strong batch of barley tea in a separate pot or kettle. Strain and discard the barley, and set the tea aside.
Combine brown sugar, white sugar, and cellulose powder in a mixing bowl. Whisk vigorously, so the powder is well dispersed.
The nurungji is done when it’s completely golden, crispy, and easily detaches from the pan. Break it up into small pieces, and wash or wipe away any excess dried starch in the pot.
Add the boricha, then slowly mix in the brown sugar mixture one spoonful at a time. Bring to a simmer over medium-low heat.
Add the creams, salt, and vanilla extract. Continue to simmer over medium-low heat for no longer than 10 minutes.
Transfer to a pourable measuring glass and let it cool for 30 minutes to thicken. It should be just thick enough so the rice bits stay suspended.
Stir before pouring into a popsicle mold, so the rice bits are evenly dispersed. Push down the popsicle sticks about 3/4 of the way down and freeze for at least 8 hours.
To release the paletas, slide a popsicle stick down the sides to loosen them. Or, place the mold in warm water for 20 seconds.
Enjoy right away, or wait 5 minutes for it to soften slightly before eating.
Notes
Crema Mexicana: In Mexico, this is simply called crema. Do not substitute it with regular sour cream (crema agria), as the high acidity will ruin the barley tea flavor.
Best Substitutes: Use a 50/50 mix of heavy cream and crème fraîche, OR a ratio of ¾ cup heavy cream to ¼ cup whole milk.
Watch the Simmer: Keep the heat low, gentle, and don't cook for too long. The more you cook it, the more starch is released into the cream base, potentially making it very slimy and gummy.
Texture Stabilizers (Optional): The starches from the short-grain rice act as a natural stabilizer to keep the paletas relatively creamy on their own. However, if you plan to store them long-term, a tiny pinch of cellulose gum or guar gum provides extra insurance against ice crystals. Avoid xanthan gum, as it can make the dairy base feel slick.
Storage & Shelf Life: Once frozen solid, unmold the paletas and wrap them individually, then store them in an airtight container. They will stay perfectly creamy and freezer-burn free for up to 1 month.