For the Banana Cupcakes:

1. Preheat oven to 350 degrees.
2. Line a standard 12-cup muffin pan with paper liners.
3. In a bowl, whisk together flour, sugar, baking powder, baking soda, and salt.
4. Thaw the bananas.
5. I let it sit out for around 20 minutes.
6. Peel the bananas and drop them in your processor.
7. Puree them until smooth.
8. A quick pulse of about 4-5 times should do it.
9. Make a well in center of flour mixture. In this, mix together oil, pureed bananas and vanilla extract.
10. Gently fold the dry with the wet ingredients until combined.
11. Dividing evenly, spoon batter into muffin cups.
12. I used a 1/4 measuring cup to divide my mixture.
13. Bake until a toothpick inserted in center of a cupcake comes out clean, 25 to 30 minutes.
14. Remove cupcakes from pan; cool completely on a wire rack.

For the Banana Cupcakes:

1. Take all the ingredients for the frosting in a medium bowl.
2. Using an electric mixer, beat it until smooth, 4 to 5 minutes.
3. Take the walnuts and dry toast them in a skillet. Chop them coarsely.
4. Use a piping bag to top the cupcakes.
5. Or you can simply spread them on top of the cupcakes too.
6. Sprinkled lightly with toasted walnuts.

Tips
1. If you do not have walnut oil, simply replace it with additional vegetable oil.
2. If using regular bananas, use additional 1/4 cup of butter or oil.

Courtesy: http://chefinyou.com/