Plastic Cupcake mold (found in the baking section of the craft store) or silicon muffin molds, also found in the baking aisle)
Clear glycerin soap (note: you can also use opaque soap as well but the colors will be more pastel)
Soap tints and soap scents
Plastic Piping bag and Wilton Tip
Melt chunks of glycerin in a microwave safe bowl in short increments in the microwave or in a saucepan over low heat on the stove.
When the soap is completely melted, add several drops of color tint and stir. Pour melted soap into the molds and let dry. When the soap has completely cooled, pop them out of the mold and attach top and bottom with a small amount of melted soap.
TIP: Make sure to divide your melted soaps into different Tupperware containers if you want to use different colors.
If you are only making the base of the cupcake in the cupcake mold and you want to frost your own cupcake without a frosting mold, simply melt the soap in a plastic container in the microwave and add your desired amount of color and tint then let thicken on your counter until it's able to put into a piping bag. Pipe just like you would a cupcake and sprinkle with glitter or edible sprinkles (that will dissolve in the shower)