Preheat oven to 325°F. Line a standard muffin tin with paper liners.
In a medium bowl, whisk together the flour, baking soda, cinnamon and salt.
In the bowl of a stand mixer, or in a large with an electric mixer, combine olive oil and sugars until thoroughly combined.
Beat in eggs until incorporated and stir in bananas, vanilla and water.
Add dry ingredients to the wet ingredients and mix until just combined and gently stir in chopped nuts.
Use a large cookie scoop to evenly distribute the batter between the prepared muffin wells.
For the Crumb Topping:
Stir all ingredients together in a small bowl. Make sure the olive oil is thoroughly incorporated.
Sprinkle each muffin with the crumble topping, pressing it in gently.
Bake in preheated oven for 20-23 minutes, or until the muffins are golden brown and slightly firm to the touch.
Allow to cool for 5 minutes in the pan, then remove to a cooling rack and allow to cool completely.
Notes
If you would like to substitute the white whole wheat flour for all-purpose flour, simply add in the same amount, but eliminate the hot water. If you're batter seems a little dry, add the water into the batter one tablespoon at a time until it is moistened.