Heat oven to 350°F. Whisk 3 eggs, until it becomes frothy.
Using fork, smash banana. Hint: Its ok, if there are any visible chunks.
Add mashed banana, to the whisked egg mixture. Add sugar and cooking oil. Whisk again until sugar dissolves completely.
To keep the dry ingredients ready, In another mixing bowl add All purpose flour, baking powder, baking soda, salt. Use whisker to blend flour evenly. Hint: Alternatively shift all the dry ingredients to make them combine evenly. But I find whisking does my job easier.
Now add this dry ingredients to the egg mixture. and the flour gently. Combine them well.
Dust the raspberries with the flour, so that the flour gets evenly coated with the flour. Add them to the batter, using spatula gently fold them. Do not over mix. Hint: This process avoid the fruits sinking to the bottom of the pan.
Grease and dust the baking pan. Hint: Pan can be of any shape, even round ones are also perfect.
Pour the mixture to the pan, arrange some raspberries on the top for decoration.
Bake it for about 30 minutes or until the inserted toothpick comes out clean. Remove it from the oven, let it cool for about 10 minutes. Then remove from the pan. Slice the raspberry banana bread, once they are cooled down completely.