Preheat your oven to 350°F (175°C).
Grease a loaf pan or a baking dish with vegetable oil or line it with parchment paper.
In a large bowl, combine the rice flour, granulated sugar, baking powder, baking soda, salt, and ground nutmeg. Mix well.
In another bowl, whisk together the eggs, coconut milk, vegetable oil, vanilla extract, and mashed banana (if using).
Gradually add the wet ingredients to the dry ingredients, stirring until just combined. Be careful not to overmix; the batter should be smooth but slightly thick.
Pour the batter into the prepared loaf pan or baking dish.
Bake in the preheated oven for about 45-50 minutes, or until a toothpick inserted into the center comes out clean.
If the top starts to brown too quickly, cover it loosely with aluminum foil.
Allow the rice bread to cool in the pan for about 10 minutes.
Transfer it to a wire rack to cool completely before slicing.
Enjoy your meal!