Preheat the oven to 350 degrees. Spray 2 8" round cake pans with nonstick baking spray.
In a mixing bowl add the sugar and butter and mix for 3 minutes until the sugar is mostly dissolved and it is lighter in color.
Add the eggs, vanilla, oat milk, bananas, and vanilla. Stir to incorporate.
Add the dry ingredients and mix until just combined.
Divide the cake batter between the two cake pans.
Bake for 30-40 minutes, until the top is golden and a toothpick comes out clean.
Allow to cool completely.
Add the sweetened condensed coconut milk to a saucepan. Cook on medium/low heat until lightly golden. Be careful not to overcook. You want the caramel runny not hard.
Allow to cool 30 minutes.
To assemble, spread 1 cup of chocolate spread to the top of the first cake. Pour half of the caramel on top. Top with chopped chocolate.
Place the second layer of cake on top and repeat the process, adding the other half of the chocolate-hazelnut spread, caramel, and more chopped chocolate.
I like to add a drizzle of caramel to each place before plating the slices of cake.