Swiss Meringue Buttercream, the Basic Buttercream recipe I've been refining does the trick. It also pipes beautifully, smooths perfectly, and tastes divine.
For Dina's school party this year I made cupcakes from a box (don't judge me!) Duncan Hines yellow cake mix (was it Classic Yellow or Butter Recipe Golden? I don't remember.) Here in Eindhoven, this can be found at Jumbo supermarket in Veldhoven or Rohit. Of course I can't just make a box cake mix without some kind of modification so I substitute a low-fat milk for the water in the recipe. I ended up with 24 cupcakes (fill them up about 50-60% of the way so you get a nice domed top) from one box, which meant, once baked, they came just over the top of the cupcake liners.
Once the cupcakes cooled, I frosted them with a Basic Buttercream. The key to any frosting is, of course, the ingredients. The butter available everywhere here in the Netherlands kicks serious ass. The powdered sugar... not so much. I've only found proper 'icing' sugar or 'Poeder Suiker' at the Genneper Park molen, and the Dommelsche molen. Those of you listening back home can use Domino 10x, you lucky people. If you are unable to get powdered sugar (do not use AH brand powdered sugar, it is too grainy and will result in frosting that has the texture of sand) you can use a food processor to process the Fine crystal sugar available at AH and sift it, many times, until you achieve the right consistency. The 10x in the Domino brand sugar stands for process and sifted 10 times. I'm lazy so I just stock up when I go to Genneper park- powdered sugar never goes bad.
Basic Buttercream Frosting
230 g unsalted butter
500 g powdered sugar (one bag)
1 tsp vanilla extract
1 tsp meringue powder (Wilton brand is what I used)
2 Tbsp water
1/8 tsp salt
Start with the butter at room temperature. Beat the butter in a mixer until it looks smooth. Slowly add the powdered sugar, scraping down the bowl after each 100 g (approximately). Once all the powdered sugar is incorporated, add the remaining ingredients. Beat well. If the frosting is too stiff, you can add more water, 1 tsp at a time.
Frosting can be left at room temperature for a few days, but should not be left in direct sunlight, or a very warm room.