Preheat oven to 375 degrees F (190 C). Lightly grease muffin tin with butter or oil. (Option: use paper liners, but the muffins may stick to them).
In a large bowl melt the butter (skip this step if using canola oil). If using a flax egg instead of a chicken egg, mix together ground flax and water in a small bowl and let sit for 5 minutes.
In the large bowl mix in the egg (or flax egg), mashed banana, grated carrot, brown sugar, milk and vanilla extract.
In a separate bowl mix together the oats, almond meal, tapioca starch, sweet/glutinous rice flour, white rice flour, salt, baking soda, and spices.
Slowly mix the dry ingredients into the wet, and stir until just combined. Gently stir in the dried cranberries and half of the walnuts.
Pour the batter evenly into 6 muffin tins. Top with the other half of the walnuts. Bake for approximately 35 minutes until the top is browned and firm.
Let the muffins cool in the pan for at least 5 minutes and then remove. They will stay fresh in a container at room temperature for a few days, or in the freezer for a few months.