Preheat your oven to 350°F (175°C).
Grease a standard loaf pan with butter or non-stick spray.
Toast the nuts in a dry skillet over medium heat for about 5 minutes.
Mash the very ripe bananas until smooth.
Incorporate the melted butter into the mashed bananas, add vanilla extract, and whisk in the eggs.
In a separate bowl, mix together the flour, sugar, baking powder, salt, cinnamon, and nutmeg.
Pour the wet mixture into the dry ingredients and gently fold them together.
Fold in the blueberries and toasted nuts.
Transfer the batter into the prepared loaf pan.
Bake for 50-60 minutes or until a toothpick inserted comes out clean.
Let it cool in the pan for about 10 minutes, then transfer to a wire rack to cool completely.