• Preheat oven to 350° F
• Prepare a 12-cup Bundt cake pan by spraying generously with baking spray. Alternatively, combine ¼ cup vegetable oil, ¼ cup flour and ¼ vegetable shortening. Using a pastry brush, apply generously to the Bundt cake pan.

Chocolate Filling

• Combine ½ cups of chocolate chips and ⅓ cup of brown sugar in a small bowl. Set aside.

Cake Batter

• In a large bowl combine flour, baking soda, cinnamon and salt. Set aside. (note: sift flour if necessary to remove any lumps)
• Place butter and granulated sugar in a mixing bowl. Using a handheld or stand mixer, mix the butter and granulated sugar until light and fluffy (approximately 2 minutes)
• Add eggs to mixing bowl and mix until well combined. Scrape the sides and bottom of bowl as needed.
• Add mashed bananas to mixing bowl and mix until well combined. Scrape the sides and bottom of the bowl as needed.
• Add ½ of the dry ingredients (flour, baking powder, salt) and mix on low speed until combined.
• Add sour cream to mixing bowl and mix on low speed until combined.
• Add remaining dry ingredients and mix on low speed until combined.
• Pour half of the cake batter into prepared Bundt cake pan. Spread evenly and make a small 'well' in the center using a dinner spoon.
• Slice a banana into ¼" slices and layer into the well you just created. Next spoon the chocolate filling over banana slices, taking care to keep the filling in the well.
• Add remaining cake batter and smooth the top.
• Bake for 50 - 55 minutes or until a toothpick inserted in the middle comes out clean. You may also check for doneness using an instant read thermometer. The internal temperature of the cake should be 190℉. Note: if the cake top begins to turn too dark, place a sheet of aluminum foil over the cake and continue baking until done.
• Allow cake to cool for 15 minutes and flip the cake over onto a cooling rack. Remove cake pan and allow to cool for another hour. After cooling, move cake onto a serving platter.

Chocolate ganache (optional)

• Place chocolate chips in a medium-sized heat-proof bowl.
• Place butter and heavy cream in a small saucepan. Place on stovetop and bring to a low boil over medium heat, stirring often.
• Removed saucepan from heat and pour over chocolate chips. Let set for 5 minutes to soften chocolate, Stir until smooth. (note: if chocolate does not melt completely, heat in the microwave for 30 seconds at 50% power. Stir until smooth)
• Drizzle or pour chocolate ganache over the banana Bundt cake.