Michelle Darmody: Brown butter or beurre noisette in baking

Brown butter is generally associated with a very traditional French style of cooking. It is better known in France as beurre noisette and is mainly used in savoury sauces for fish or chicken, but now it is having a moment in baking. It adds an additional richness to recipes and a lovely golden colour, and it works particularly well in icings such as buttercream.
To make a beurre noisette buttercream cool the browned butter down after it is made, so that it re-solidifies, and whip it with your icing sugar.