Cut the cake base horizontally in 3 equal layers.
Place one layer on a serving plate. Sprinkle it with 1 tbs orange juice. Evenly spread half of the orange mousse on top. Cover with a second layer, sprinkle orange juice and spread the remaining orange mousse on top. Place the third layer, again sprinkled with juice. Spread the Peach Buttercream Frosting all around the top and the sides of the cake. Transfer the cake to the fridge for few hours.
Before serving make a caramelised butter: in a small saucepan over medium heat combine brown sugar, butter and 2 tbs orange juice. Whisk until the butter and the sugar are completely melted.
Let the caramel cool for 2-3 minutes and spoon it on top of the cake, around the sides so that it starts dripping down. Decorate with fresh fruits on top.