Preheat oven to 350F Begin by melting the butter and brown sugar in a pot over medium-low heat. Add the spices and vanilla, then wait for the caramel to bubble and reach soft ball stage. (When you drip some of the caramel into a bowl of ice water, it’ll form a nice, malleable ball, hence, soft ball stage) Pour the caramel into a 9-inch cake pan. Layer the bananas on top, and set aside. Begin the cake by creaming the butter and sugar together until you get a creamy and pale mixture. Add the agave nectar and banana (I substituted half the sugar and butter in the original recipe with these ingredients), and mix until incorporated. Add the egg yolks, vanilla extract, and milk and mix. In another bowl, mix together the flour, baking powder, and salt. Gradually incorporate the dry flour mixture into the wet ingredients. Gently mix together until incorporated. With the egg whites, whip/whisk with 1 tsp icing sugar (just to stabilize it) until you get stiff peaks that point straight up when you lift the whisk. (kind of like meringue would) Gently fold the egg whites into the cake batter. You don’t want to punch out all of the air from the meringue by mixing. Pour batter on top of the caramel/bananas and pop that badboy in the oven for about 40 minutes. The top will get nice and browned (I had to turn my cake around 25 minutes in because the heat is uneven in my oven). PUT A LARGE PAN UNDERNEATH! My cake pan is short, so the caramel started to drip out halfway through baking. Put the pan in or else you’re going to have an unpleasant time cleaning the inside of your oven. Burnt sugar = not fun. Once the cake is done, take it out and let it sit for about 20 minutes. I know it’s hard to wait, but if you pop it out right away, the caramel will just ooze everywhere and not be on your cake to put in your mouth. Sad time. Before you turn it over, quickly run a sharp knife around the edges to loosen the cake. Flip over onto a cake stand/plate and cut into that cake! Omnomnom.