Cover cookie sheet with waxed paper. Place shovels on waxed paper. In 1-quart saucepan, melt baking chips and shortening over low heat, stirring occasionally, until smooth; remove from heat. Place 4 or 5 marshmallows in bottom portion of shovel to look like pile of snow. Spoon melted white chocolate over marshmallows and bottom portion of shovel; sprinkle with sugar crystals. If desired, drizzle white chocolate over shovel handle. Let stand until chocolate is firm.