Cinnamon crunch muffins
3 large ripe bananas
1/3 cup plain nondairy yogurt
1/3 maple syrup
1 1/2 teaspoons baking powder
1 teaspoon ground cinnamon
1/2 teaspoon baking soda
1/2 teaspoon fine grain sea salt
1 1/2 cups spelt flour
1/4 cup chocolate chips, optional
4 to 5 teaspoons turbinado sugar (or another large-crystal sugar, such as demerara)