We have a lot of humidity here, I use half butter, half shortening and milk and cream, pretty much the Wilton recipe but I use 5 cups icing sugar and 1 1/2 tsp. vanilla. However cake decorated with this recipe should be kept at a room temperature of below 75F and at 83F the butter starts to break down and melt.
Have you tried the Whimsical Bakehouse Buttercream, not the Meringue one, the one with the high fat ratio/ Again, since there is butter in it, you need to make sure your temperature is not above 83F.
Jeanne G's chocolate buttercream recipe from the Wilton site, is well liked.
Here is a copy of her post:
This is my all-purpose chocolate frosting, and I use it when I am going to smooth the frosting, and to pipe stars, and when I am going to spatula swirl it. I use it as a base for black frosting, too.
I have no qualms about a cake with this frosting sitting out a few days, but I store leftover frosting in the refrigerator for maximum freshness. If I havent used it up within about two weeks I think up a project for it. Recently I used up some leftovers by filling a layer cake with it, and then frosting the cake white. (I have happy grandchildren.) This recipe works in a 4.5 quart KitchenAid stand mixer.
First, about the ingredients
Butter: I use unsalted because I really prefer its taste on bread and in many recipes. (I dont know whether I could tell the difference in this recipe because Ive never had salted on hand when Ive made it.) I keep butter refrigerated until Im ready to use it. In my microwave 15 seconds on full power is just right to soften a pat for my morning toast or a stick and half for this recipe.
Powdered sugar: To avoid sifting and measuring, all my frosting recipes use a 2 pound bag. I buy what is on sale, without regard to whether the sugar started life in canes or in beets.
Cocoa: I have made many successful batches of this recipe using Hersheys cocoa. One of my sons worked in Chicago a couple of years, where he fell in love with Chicago-style pizza, blues, and Bloomers chocolate supply store. Whenever he is back in Chicago he has pizza, visits a blues bar, and makes a chocolate run. Last time he brought me back 2-pound bags of each of the three kinds of cocoa they carry. Oh my! Each is wonderful and has its own flavor and color nuances. If you dont have someone to make chocolate runs for you and youd like to venture beyond Hersheys, try the web site: www.blommerstore.com
. I measure cocoa first and then put it through a sieve into my mixing bowl, to eliminate any lumps.
Liquid: I make this with water, but you may use milk if you prefer. I start with ½ cup measured out, and add almost all of it. If necessary I add the remainder after mixing. Sometimes it takes more than the ½ cup total. I find that chocolate frosting takes more fiddling with the water content than white buttercream does.
Tip: It is hard to get the exact same shade of brown in different batches of frosting. If youll need more than one, make them all upfront and stir them together in some huge container (I use a stock pot) so the color is uniform.
Now, the simple recipe
3/4 cup Crisco
3/4 cup butter, softened (6 ounces, 1 & 1/2 American sticks)
1 1/4 cups cocoa
1 1/2 teaspoon vanilla
2 pounds powdered sugar
about 1/2 cup of water, give or take a little
(If you have a splash guard for your bowl, this is a good recipe to use it with.)
Mix the Crisco and butter at a slow speed until creamy.
Add the cocoa. Mix again until the cocoa is all incorporated.
Add the powdered sugar, vanilla, and most of the water. Beat at medium speed for a few minutes.
Test the spreadability and add water if necessary.