A Pâte à Bombe is the French term for a mixture used as a base for making chocolate mousse and other mousse-like desserts. This term is used for egg yolks beaten with a sugar syrup, then aerated. It is the base used for many mousse and buttercream recipes. It is made by pouring a sugar syrup that has been cooked until it is 121 degrees celsius (249.8 farenheit) over egg yolks and whipping the mixture until it is completely cold and has transformed into a uniform, unctuous, airy mass.