In a large bowl mix together rolled oats, yogurt and milk. Let soak for 10 minutes. Mix flour, salt, spices, baking powder and baking soda in a bowl. Add brown sugar, mashed banana, egg and oil to yogurt/oat mixture. Mix well. Add dry ingredients to the rolled oats mixture. Mix well. Fill greased or paper lined muffin cups 2/3 full. Bake for approximately 20 minutes. If needed bump the temperature up to 375 for another 10 minutes to get a nice crunch on top and done all the way through. While muffins bake, mix topping ingredients well and spread frosting on cool muffins, if you can wait that long.