Combine the butter and sugar in the bowl of a stand mixer fitted with the paddle attachment and cream together on medium-high for 2-3 minutes. Scrape down the sides of the bowl, add the egg, and mix on medium-high again for 2-3 minutes.

On very low speed, add the bananas and mix for 45-60 seconds to ensure all the bananas are broken down.

Still on low speed, add the flour, baking powder, baking soda, and salt, and mix for 45-60 seconds, just until your batter comes together and any remnants of dry ingredients have been incorporated. Scrape down the sides of the bowl.

Pour the batter into the prepared quarter sheet pan and, using a spatula, knife, or the back of a spoon, spread the cake batter in an even layer.

Bake the cake for 25-30 minutes, rotating the pan halfway through baking. The cake will rise and puff, doubling in size, but will remain slightly buttery and dense.

- At 25 minutes, use your finger to gently poke around the outside and center of the cake. It should bounce back very slightly and not be jiggly at all. Leave the cake in the oven for an extra 3-5 minutes if it doesn’t pass these tests.

When baked through, remove the cake from the oven and allow to cool to room temperature on a wire rack or, in a pinch, in the fridge or freezer (don’t worry, it’s not cheating). The cooled cake can be stored in the fridge, wrapped in plastic wrap, for up to 5 days.

Preheat oven to 350 degrees. Spread nuts over an aluminum foil lined baking sheet. Roast nuts for 8 to 10 minutes.

Stir together sugar, cinnamon, salt, and milk in a medium saucepan. Cook over medium-high heat for 8 minutes. Remove from heat, and stir in vanilla immediately. .

Immediately after, add walnuts to sugar syrup, and stir to coat well. Spoon nuts onto waxed paper, and separate nuts with a fork.

Combine the butter, shortening, and cream cheese in the bowl of a stand mixer fitted with the paddle attachment and cream together on medium-high for 2-3 minutes until the mixture is smooth and fluffy. Scrape down the sides of the bowl.

Add the glucose, corn syrup, and vanilla, and with the mixer on its lowest speed, paddle them in until fully incorporated. Crank the mixer up to medium-high and beat for 2-3 minutes until the mixture is silky smooth, glossy, and white. Scrape down the sides of the bowl.

Combine the confectioners’ sugar, salt, baking powder, and citric acid in a medium container or bowl and add to the stand mixer bowl. Starting on low, mix just until incorporated.

- Scrape the bowl and crank the speed back up to medium-high. Beat for at least 3 minutes until you have a stark white, beautifully smooth and fluffy frosting. It should look just like it came out of a plastic tub at the grocery store!

Use the frosting immediately or store it in an airtight container in the fridge for up to 1 week. If you store it in the fridge, be sure to loosen it up before using or it will be impossible to spread. The easiest way to do this is by putting the frosting in the bowl of a stand mixer fitted with the paddle attachment and beating it on medium speed for 3-4 minutes.

Melt butter in a large skillet over medium-high heat. Add brown sugar, nutmeg, cinnamon and heavy cream and stir until sugar is dissolved. (about 2-3 mins)

Pour rum into a metal spoon, then use a lighter to light the rum. Be careful, the flame can get somewhat high. Once lit, pour into the pan and allow it to cook, swirling the pan a few times to disperse the rum and flames. It should burn out within a minute or two, but if not, swirl a little more to help it burn out.

Continue cooking another 1-2 minutes to thicken sauce.

Remove from heat, whisk another minute, then pour in the sliced bananas and stir until bananas are coated. Let it cool before it is used.

Place a piece of parchment or a baking mat on the counter. Loosen the cooled cake from the sides of the sheet pan and flip it upside down on the countertop. Peel off the parchment stuck to the cake and discard it.

Use your cake ring to stamp out 2 circles from the cake, one from the upper right-hand corner and one from the lower left-hand corner (or lower right-hand and upper left-hand corners), which will form the top and middle layer of the cake. Use the ring to stamp out two half-circles from the remaining sponge, which will come together to make the bottom layer of the cake. Make sure to plan out your circles to make sure you know exactly where to stamp before completing this step — you can mark them lightly on your sponge using your cake ring.

Clean the cake ring and place it on the 8-inch cardboard round, or any other cake board, platter, or parchment-lined pan. Use 1 strip of 5-6" tall acetate to line the inside of the cake ring.

Place the two half circles of cake together inside the ring, spongey side up, and fill the gap between them with additional pieces of cake scrap.

Spread one fifth of the frosting in an even layer over the cake using the back of a small spoon that fits into the acetate collar, or a spoon you've bent into a ladle-like shape. Use figure-8 motions and try to not pick up your spoon as you work.

Spread some of the Foster Sauce and Bananas on top of the frosting

Then add another fifth of the frosting on top of the foster sauce layer.

Next place your middle cake layer on top of the frosting, passing it through the acetate collar at an angle to help it nestle into place.

Repeat the same process with the frosting and foster sauce and cake. The following order from Bottom to Top should be followed: Cake, Frosting, Foster sauce, Frosting, Cake, Frosting, Foster sauce, Frosting, Cake, Frosting.

Decorate the top with the candied walnuts.

Transfer the cake to the freezer and freeze for a minimum of 3 hours (or overnight) to set the cake and filling. The cake will keep in the freezer for up to 2 weeks.

When Ready to serve, gently peel off the acetate and transfer the cake to a platter or cake stand, or whatever you want to serve it on. Let it defrost for 2-3 hours. Wrapped well in plastic, the cake can be refrigerated for up to 5 days.