My son asked for root beer float flavored cupcakes for his birthday. We tried a recipe off www.allrecipes.com that he liked the cake but not the dream whip icing. To my taste and my husbands taste the frosting tasted just like the foam on top of the float. I am looking for a recipe for buttercream that tastes kinda like vanilla ice cream. I usually make American buttercream but am trying to branch out tho. cupcakes will probably be displayed indoors so shelf stable needs to be just couple hours out of the frig. Theme is sharks so a non crusting  butter creme works as wall as crusting for me I think as the decoration is waves with shark fins made out of candy clay and confetti fish is I can find them in colors other than electric colors.

I definitely recommend Italian or Swiss meringue buttercream. I think with a little extra vanilla extract, it tastes just like ice cream.

http://www.cakecentral.com/recipe/42032/cakeloves-italian-meringue-buttercream

http://www.cakecentral.com/recipe/29598/buttercream-swiss-meringue

I love Swiss meringue buttercream as well. Another option is to make ABC but start out by taking the butter and whipping it your mixer for 6-10min. You want it to be a very very pale yellow color, then add your vanilla and powdered sugar and cream. When you whip the butter this much it gets really creamy. I made it once for a strawberry cake and added a little strawberry puree and everyone said it tasted just like strawberry ice cream.

Swiss bc tastes kinda like ice cream to me when it is really cold. :) 

sykescakes, Thanks for the information on whipping the butter for 6-10 minutes. I never thought or knew to do that!! I am going to try that next time!!

Think I will try the Swiss chilled this weekend. Personally, I think there is too many other sweets planed to use ABC. Besides cupcakes will have cookies, candy plus lunch. But knowing most of the kids will gravitate to sweets. Glad I still have time to get the cupcake rights.

I will caution you that when SMBC is chilled the consistency changes. Because of the large amount of butter it can get pretty hard. Just something to keep in mind.

Toba Garrett's French Vanilla BC is wonderful and tastes just like ice cream.  It pipes beautifully and stands up very well.  It is in her book the well decorated cake and also online.  It is one of the buttercreams made with flour.  

http://blog.ice.edu/2013/04/19/recipe-toba-garretts-almond-paste-french-vanilla-buttercream-cake/

the recipe above makes a huge amount, but you can cut it down.  In her book the amounts are

1 1/2 cups granulated sugar

3/4 cup milk

1 1/2 Tbsp flour

1/4 tsp salt

1 Tbsp vanilla

3/8 cup whipping cream

1 1/4 lbs unsalted butter

same directions.  Hint - when adding flour to hot milk and sugar, add a little milk and sugar first to the flour and mix well.  Then add that to the rest of the hot milk.  Otherwise, very difficult to get the lumps out!

two words -- vanilla paste -- that's all you need to add to any recipe