1. Grease three 8 inch round cake pans and preheat oven to 350°F (176°C).
2. Beat the butter and sugar until light and fluffy, about 3-4 minutes. Do not skimp on this step. Cream the butter for the full 3-4 minutes.
3. Add vanilla, sour cream and vegetable oil and mix until well combined.
4. Add eggs and egg white in two batches, mixing until well combined.
5. Combine dry ingredients in another bowl. Add half of the dry ingredients to the batter and mix until well combined.
6. Add the mashed bananas and mix until well combined.
7. Add remaining dry ingredients and mix until well combined.
8. Divid batter evenly between the cake pans and bake 24-26 minutes or until a toothpick inserted comes out with a few crumbs.
9. Remove cakes from oven and allow to cool for 3-4 minutes, then remove to cooling rack to cool completely.

WHEN THE CAKES ARE COOL, MAKE THE FROSTINGS:

1. Beat the butter and shortening together until smooth.
2. Add the powdered sugar in 3 batches, mixing until smooth between each. About half way through adding the powdered sugar, add the water and mix until smooth. Frosting will be fairly thick.
3. Set aside 1 cup (240g) of frosting to make the chocolate frosting, then another cup (240g) of frosting to make the strawberry frosting.
4. Add the vanilla extract to the remaining frosting and mix until smooth. Set aside.
5. Add the 2 tablespoons of muddled strawberries to one of the cups of frosting and stir to combine. Add a little bit of pink icing color to the frosting to get a nice shade of pink, if desired. Set frosting aside.
6. Add the cocoa powder to the remaining cup of frosting that had been set aside in step 3 and stir to combine. Add an additional 1-2 tsp of water to thin out the frosting a bit, if needed.

TO LAYER AND FROST THE CAKE:

1. Use a large serrated knife to remove the domes from the tops of the cake layers so that they are flat.
2. Place the first layer of cake on your serving plate or on a cardboard cake circle.
3. Place a layer of sliced bananas on top of the cake, then sprinkle the chopped nuts over the bananas.
4. Spread the chocolate frosting into an even layer over the bananas and nuts.
5. Add the second layer of cake on top of the chocolate frosting.
6. Using some of the vanilla frosting, pipe a dam around the edge of the second layer of cake.
7. Place a layer of sliced strawberries inside the dam, then fill in the dam with the strawberry frosting.
8. Set aside 1 cup (240g) of vanilla frosting. It will remain white and be used on top of the cake later. Color the remaining frosting yellow.
9. Frost the outside of the cake with the yellow frosting. For help getting a smooth finish, refer to my tutorial on how to frost a smooth cake with buttercream.

TO FINISH OFF THE CAKE:

1. To make the chocolate ganache, add the semi sweet chocolate chips to a small bowl.
2. Heat the heavy whipped cream until it begins to boil, then pour it over the chocolate chips. Allow it to sit for 2-3 minutes, then whisk until smooth.
3. Use a spoon to place the ganache around the cake, drizzling it down the sides in several spots.
4. Use an offset spatula to even out the top of the cake and smooth the ganache. Set the cake in the fridge to allow the ganache to set a bit while you make the pink ganache.
5. To make the pink ganache, put the pink candy melts into a medium sized bowl.
6. Heat 6 tbsp of heavy whipping cream until it begins to boil, then pour it over the candy melts. Allow it to sit for 2-3 minutes, then whisk until smooth. If it seems a bit thick, add another 1/2-1 tablespoon of heavy whipping cream. Note that the texture of this ganache will be a little different than the chocolate one because of the candy melts.
7. Pour the pink ganache onto the top center of the cake, then use an offset spatula to spread it to the edges and over the sides.
8. Allow the chocolate ganache to set up in the fridge for 15-20 minutes.
9. Pipe the remaining white vanilla frosting into swirls on top of the cake. I used Ateco tip 844, but Wilton 2D or 1M would work as well.
10. Top the frosting swirls with cherries, then add sliced bananas, some nut and sprinkles to the top of the cake.
11. Refrigerate cake until ready to serve. Best served at room temperature. Cake is best for 2-3 days.