Preheat oven to 350° F with oven rack positioned in the middle.
Lightly grease a bread pan with butter to ensure the bread doesn't stick.
In a large bowl, whisk together the flour, sugar, baking soda, baking powder, salt, and cinnamon.
In a different bowl, whisk the eggs until they are frothy.
To the eggs, add the mashed bananas, melted butter, and finally, the beer.
Mix well so there are no large chunks of banana left behind.
Add the wet mix to the dry mix and stir well to combine, but don't over-mix.
Fold in the cashews with a spatula; scrape the mixture into the greased bread pan.
In a small bowl, mix together the ingredients for the crumbled topping.
Evenly sprinkle the crumbled topping over the top of the bread mixture.
Bake for approx. 40-45 minutes.
Once done, allow to cool for approx. 30 minutes before taking it out of he bread pan.
Once cooled, the bread should slide right out of the pan.