whipped cream icing
how do you get whipped cream to stabilize to make an icing for a cake?
technically it would be frosting, not icing (which is typically thinner in consistency). anyway, it's all in the temperature. *everything* - the cream, the bowl, the beaters - has to be extremely cold.
most basic recipes call for heavy whipping cream (36-40% butterfat), sugar, and flavoring (e.g. vanilla or other extract, cocoa, fruit puree). whatever recipe you use, combine the ingredients in the bowl, cover it, and chill the bowl with the ingredients AND your whisk or the beaters from your mixer for at least 30 minutes in the fridge. to make the frosting, whip to stiff peak stage.
I agree with the butter fat and cold temperature issues previously discussed. You can also help stabilize your whipped cream frosting using 1 tsp. unflavored gelatin to each cup of VERY COLD whipping cream. A little powdered sugar (a pinch or two per cup of cream) will also help.
Rose Levy Bernbaum's Cake Bible has several recipes for stabilized whipped cream if you want something that really holds up for a long time. But I've found simple whipped cream does fine if it doesn't have to sit for long.