Preheat oven to 375 degrees.
Use a muffin tin that makes 12 regular sized muffins. Line the muffin tin with bleach free muffin liners.
To make the chia egg, ground 1 tbsp chia seeds (we use a coffe grinder reserved for spices). Add to a small bowl with 3 tbsp of filtered water. Stir and let sit for about 10 minutes while you are making the rest of batter. The 'egg' should be gelatinous.
In a medium sized bowl, mash bananas well. Add yogurt, milk, maple syrup and vanilla. Put aside and add the chia egg once ready.
In a large bowl, mix flours, oats and baking powder. Add in raspberries and mix to combine.
Add wet ingredients to the dry ingredients and stir with a wooden spoon or spatula until just combined.
Divide the batter among the 12 muffins. We use a spring form ice cream scoop to make this job easier.
Place in oven and bake for about 22 minutes. Check the muffins doneness by placing a toothpick or metal skewer in the center of one of the muffins. If some batter sticks to it, leave the muffins in the oven for a couple of minutes more and check again until done.
Remove the tray from the oven. Remove the muffins from the tray and place them on a metal rack to cool. If you leave the muffins in the tray, they will sweat and the bottoms will become soggy.