Hummingbird Cake

FOR THE CAKE:
Preheat the oven to 350 degrees.

Butter three 9-inch springform cake pans and line with baking parchment or waxed (greaseproof) paper.

Combine the bananas, oil, eggs, pineapple slices, and pineapple juice in the bowl of a food processor and process until combined. Transfer to a large bowl and fold in the remaining ingredients. Pour into the prepared pans, dividing the batter evenly. Bake for 30-35 minutes, or until the cakes come away from the sides of the pan. Let the cakes cool in the pans for 10 minutes before turning out onto a wire rack to cool completely.

FOR THE ICING AND FILLING:
Process the butter, sour cream, sugar, and cream cheese until smooth and combined, about 1 minute. Do not overprocess as it will become runny.

TO ASSEMBLE THE CAKE:
Place the bottom layer on a serving plate and cover with one-third of the icing. Spread with half of the mango slices. Top with the second cake layer and repeat, using another third of the icing and all of the remaining mango slices. Place the third cake layer on top and cover with the last of the icing. Decorate with the fresh flowers, if desired, and serve.