Combine whole wheat flour, all-purpose flour, baking
soda, baking powder, and salt in one bowl and set aside.
In another bowl, lightly beat the eggs. Add the sugar
and beat until smooth.
Blend in to the egg mixture the yoghurt, oil, vanilla
and mashed bananas.
Add the egg mixture to the dry ingredients and mix
until just combined.
Add the nuts and stir until combined.
Place in lightly greased 12 cup or 24 cup muffin tin
Bake at 350 F for about 25 minutes, until tops are
lightly browned or muffins are firm to touch.