Moist banana coffee cake is made with sour cream, vegetable oil, and ripe mashed bananas (meaning this coffee cake is very moist!) We add cinnamon to the batter, and a brown sugar cinnamon streusel on top that once baked get crunchy and adds the perfect compliment in taste and texture to the moist and fluffy banana coffee cake!
Preheat oven to 350°F. Spray a 9x13” baking dish with nonstick cooking spray. Set aside.
Make the Crumble
Stir the flour, brown sugar, and cinnamon together to combine. Pour the melted butter overtop and using a fork, mix to combine. Place in the fridge to chill while you make the cake batter. We want the butter to harden before breaking it up and placing it overtop of the banana batter.
Make the Batter
In a large bowl mix the flour, baking soda, cinnamon, and salt.
In a medium bowl, or bowl of a stand mixer fitted with paddle attachment. Beat the butter and sugars on medium speed for 2 minutes. Add the eggs, vanilla, sour cream, vegetable oil, and mashed bananas and mix until combined. Add the dry ingredients and mix until no flour streaks remain, but don’t overmix!!! Pour the batter into the baking pan and spread into an even layer.
Remove the crumble from the fridge. Evenly distribute the crumble along the top of the batter, using your hands to break the crumble apart into small pieces as you go.
Bake for 40-45 minutes or until a toothpick inserted in the center comes out clean.
Remove from oven and let cool slightly before cutting and serving.
Video
Notes
Store covered or in an airtight container at room temperature for up 3-4 days.