I've always wanted to give brown butter a go, considering all the cheffy types love the flavour and believe it adds so much to sweet or savoury food. So I used it in this cake and frosting - rather excessive I thought but it makes an impressive cake! It's from Jill O'Connor's Cake, I Love You (Chronicle Books, 2017). The beurre noisette brings an extra depth of caramelness to the banana.

330g unsalted butter
3 c flour (I used spelt)
2 tsp baking powder
1 tsp baking soda
1 tsp sea salt
4 eggs at room temperature
1 1/2 c brown sugar
1 c granulated sugar (I used coconut)
2 c mashed bananas
3/4 c sour cream or yoghurt
2 tsp vanilla extract
3 tbsp dark rum, optional (or brandy or bourbon)

For icing/frosting:
220g unsalted butter
450g cream cheese at room temperature
1 tbsp vanilla paste
1 tsp vanilla extract
2 tbsp dark rum, optional
pinch sea salt
6 to 8 c icing sugar

Preheat oven to 180C. Line 2 (23cm) or 3 (20cm) round cake tins with baking paper. Mine are actually 18cm round, which makes for a tall 3-tier cake.
In a small saucepan over low heat, melt the butter, Once melted, turn up the heat and bring to a boil. Boil for about 5-7 minutes, stirring with a wooden spoon, until the the milk solids at the bottom of the pan begin to brown and the butter develops a nutty aroma. Take off the heat immediately and transfer to a bowl to cool.
Sift flour, baking powder, baking soda and salt in a medium bowl.
In a large bowl beat eggs until frothy with a handheld electric mixer or stand mixer. Slowly add the sugars and continue beating until thick and doubled in volume, about 3-4 minutes. Mix in bananas, sour cream, vanilla and rum. Add half the dry ingredients and mix for a few seconds then add the rest and mix until just combined. Fold in brown butter with a spatula. Divide batter equally between your cake tins and bake for 35-40 min (for 2 tins) or 25-30 min (for 3 tins). This is now a good time to make the brown butter for your icing.
When cakes are cooked through transfer tins to a wire rack for 10 minutes then turn out onto the rack to cool completely.

To make the icing, make the brown butter as above. Transfer to a bowl, cover and refrigerate until firm, about 30 minutes.
In a large bowl mix by hand or electric mixer the cream cheese and butter. Beat in the vanilla and salt and 4 cups of the icing sugar until smooth. Mix in rum. Your icing should be thick but spreadable. If it's too soft add as much of the icing sugar you need to reached your desired consistency. Set aside.

Once cakes are cooled place the first layer bottom side up on your serving plate or cake board. Top with about one third of the icing for a 2-tier cake or a quarter of the icing for a 3-tier cake. Top with your second cake layer and repeat. Refrigerate your stacked layers for 30 minutes to firm up. Then apply a thin coat of icing on top of the cake and around the sides to make a crumb coat. Place back in fridge for another 15-20 minutes to set. Spread final layer of icing on top and the sides.
Serve immediately or refrigerate covered. Allow cake to come to room temperature again before serving.

This is a great occasion cake; at least take your time to devour a piece with a hot cup of something. I actually had a slice for breakfast! Then bookended the day with another piece for dessert. Hey, don't judge me!