Preheat the oven at 180 C / 350 F.
In a bowl, mix together all purpose flour, whole wheat flour, salt, baking powder, baking soda. Transfer to a plate.
In the same bowl, mash the bananas well using a masher.
Add sugar, vegetable oil, vanilla essence and mix well.
Add the flour mixture in 2 batches and mix gently till there is no dry flour patches left.
Add in toasted walnuts, butterscotch chips and mix gently.
Line a muffin pan with paper liners or grease them with oil or butter.
Scoop the batter into the paper cups till 3/4th full.
Place the pan in the preheated oven and bake for 30-35 minutes or till a skewer inserted comes out clean.
Eggless banana muffins with walnuts are ready.
Take the pan out of the oven and let the muffins cool down to room temperature before serving.