Preheat your oven to 350°F.
Whisk the flour, baking soda, and baking powder together, and set aside.
3 cups All purpose flour, 2 teaspoon Baking soda, 2 teaspoon Baking powder
Add the brown sugar and cinnamon to a small mixing bowl, and combine.
½ cup Dark brown sugar, 2 teaspoon Ground cinnamon
Add the softened butter and granulated sugar to a stand mixer bowl. Using the paddle attachment, cream the butter and sugar for 1-2 minutes until combined.
1 cup Butter, 2 cups Granulated sugar
Add the eggs, and continue to mix with the paddle attachment until combined.
2 large Eggs
Add the sour cream, mashed bananas, and vanilla extract to the stand mixer bowl, and mix on low until combined.
6 Bananas, 1 cup Sour cream, 2 teaspoon Vanilla bean paste
Add the dry ingredients to the mixer, and mix on low until the batter has come together.
Remove the bowl from the stand mixer, and fold in half the semi-sweet chocolate chips using a rubber spatula.
1 cup Semi-sweet chocolate chips
Grease a 9x13 baking pan with butter. Pour half the batter into the pan, and sprinkle half the cinnamon sugar mixture in a layer on top of the cake batter.
Pour the remaining cake batter over the cinnamon sugar layer. Sprinkle with the remaining cinnamon sugar and chocolate chips.
Bake the cake for 45-50 minutes until the middle of the cake is firm.