Making a mountain out of cupcakes may sound easier than it is. One thing you must consider before making your cupcakes into a mountain is whether or not they will be individually frosted or held together with frosting and fondant. Using frosting and fondant will make the cupcakes appear as one cake, rather than individual cupcakes. However, it will make the mountain look more like a mountain.
Bake your cupcakes. Don't use muffin papers in your muffin pan when baking. Grease the pan instead and leave the cupcakes without individual papers.
Frost your cupcakes with your chosen frosting, if you will be serving them as cupcakes instead of as a part of a larger whole cake.
Form the base of your mountain by placing a circle of cupcakes around your serving platter or a cardboard cake circle. Fill in the circle with cupcakes.
Place a piece of parchment paper or waxed paper over the base layer of cupcakes. Don't cover any cupcakes that will be showing. You will still lose some frosting when this layer is removed, but it will be much less than if you used cling film or none at all. Parchment paper also helps hold the cupcakes up evenly, instead of them being smushed between a top and bottom cupcake.
Place another layer of cupcakes across the parchment.
Continue building your mountain in this fashion--layering parchment over frosting and then a layer of cupcakes--until your mountain is the height you desire.
Place your fondant over the stack of cupcakes, if you are going to decorate the piece as one cake, and decorate as you like. The frosting underneath is then your glue for the fondant. If you are covering the stack of cupcakes with fondant, you don't have to put pieces of parchment between each layer, but it is recommended if you'll be taking the fondant off and serving the cupcakes individually.