Brown Butter Layer Cake

This cake is made with a vanilla bean frosting and is meant to be topped with a drizzle of salted caramel sauce. The recipe is also from an Australian blog, hence the measures in grams.

Makes a 4-layer 6" or a 3-layer 7", 2-layer 8" cake

For the brown butter cake:
300g (2 & 2/3 sticks) butter (I used salted, add 1/4 tsp salt if using unsalted)
360g (approx 2 & 1/2 cups) plain/all-purpose flour
4 tsp baking powder
240ml (about 1 cup) milk
2 tsp pure vanilla extract
330g (approx 1 & 1/2 cups) granulated sugar (I used caster/superfine)
4 large eggs

Prepare the brown butter ahead of time as you will need to chill it:
Place butter in a small saucepan on low-medium heat and stir until it melts completely.
Continue cooking, stirring frequently until the milk solids turn brown and the butter smells nutty, about 5 minutes longer (or as long as it takes to turn golden brown). Take care not to burn (it will continue to brown even after you remove it from the heat, so take it off early).
Scrape the melted butter and browned bits into small bowl and chill until solidified (about half an hour in the freezer, an hour or so in the fridge). When ready to make cake, remove from the fridge long enough that the butter is soft enough to be beaten with an electric mixer.

For the cake:
Preheat oven to 180°C (350°F) and grease four 15cm (6 inch) or three 18cm (7 inch)  or two 8 inch round cake tins. Line the base of the tins with baking paper.
Combine flour and baking powder in a medium bowl and set aside. Mix milk and vanilla together in a measuring jug.
Using an electric mixer on low speed, beat sugar and brown butter in a large bowl until blended. Increase speed to high and beat well until very pale and creamy, at least 5 minutes.
Reduce speed to medium low, add eggs 1 at a time, beating well after each addition.
Alternately add flour mix and milk mixture, beginning and ending with flour mixture (I did it by adding 1/4 of of the dry mixture followed by 1/3 of the wet mixture at a time). Beat until smooth, occasionally scraping bowl with a spatula.
Pour equal amounts of mixture into prepared tins and bake until a skewer inserted into the centre comes out clean and the outside is golden, about 30-35 minutes (will vary depending on your cake tin size). Take cake not to overbake or cake will be dry.
Cool in tins for 15 minutes, then carefully turn out on to a wire rack to cool completely. Can be stored in an airtight container overnight if you want to prep the cakes a day ahead.

For the icing:
400g salted butter (add 1/4 tsp salt if using unsalted), softened
600g icing sugar (confectioner's sugar), sifted
1/3 cup milk
2 vanilla bean pods, seeds scraped (or 2 tsp vanilla bean paste)

Place butter in a large mixing bowl and beat with an electric mixer on high.
With the mixer on low, gradually add icing sugar and mix until incorporated.
Add vanilla bean seeds and milk and beat on high until very pale and fluffy.
Place first layer of cake on your cake stand or plate. Spread a layer of icing over the top of the cake, using an offset spatula. Sandwich with another layer of cake and then repeat with remaining cake layers.
Crumb coat cake and then chill cake for about 30 mins.
Cover cake with the remaining icing and chill again for another hour before pouring salted caramel over the top of the cake.
Keep cake chilled in the fridge, remove 30 mins before serving to allow it to come back to room temperature.