Bake the cupcakes according to the box directions using white liners. Let cool completely.

Make the frosting: Beat butter until creamy. Gradually add powdered sugar, vanilla, and heavy cream. Beat on high until light, fluffy, and stiff enough to hold a shape.

Pour the blue, yellow, and pink sanding sugars onto a small plate, creating three separate color wedges.

Using a piping bag, pipe a high, thick, rounded dome of frosting onto each cooled cupcake.

Immediately take the frosted cupcake and press the frosting dome directly into the tri-colored sugar. Gently roll it until the entire dome is coated and looks like crushed ice.

Insert a small plastic tasting spoon into the top of each cupcake and serve.