Are these gluten-free?
The core structure comes from sweet rice flour (Mochiko), which is naturally gluten-free. However, “gluten-free” as a dietary requirement depends on all ingredients and cross-contact. If you are baking for someone with celiac disease, use ingredients that are certified gluten-free when possible (especially baking powder, vanilla, and any add-ins) and avoid shared equipment that has touched wheat flour.
What is Mochiko, and can I swap another rice flour?
Mochiko is sweet rice flour (also called glutinous rice flour). It is not the same as regular rice flour. Regular rice flour will not give you that bouncy chew. Look for Mochiko in the Asian foods aisle or online.
Why did my muffins turn out cakey?
Common culprits: the batter was under-mixed, the Mochiko was under-measured, or the oven ran cool. Mochiko needs thorough mixing to hydrate evenly. Also, measure by weight if you can. For the cups-based ingredients, level them off (especially sugar), since a heavy hand can throw off the texture.
Why did they sink in the middle?
Usually it is too much liquid, underbaking, or opening the oven early. Bake until the centers spring back and a toothpick comes out mostly clean with a few moist crumbs (no wet batter streaks).
Can I make them dairy-free?
Yes. Swap the butter for melted coconut oil or a dairy-free butter alternative, and use full-fat canned coconut milk or a plant milk. The flavor shifts more coconut-forward, which is not a problem in my book.
Do I need muffin liners?
You can use them, but you will lose some of the crispy edge magic. Greasing the pan well gives you that caramelized perimeter and an easier release.