Beat egg whites in a mixer or with a hand mixer until they begin to turn white in color. Slowly add in powdered sugar ¼ cup at a time. Play with the consistency. Some like thier snow with more definition, and may want to add a little more. Others might like their snow soft, which may mean a little less sugar.
Use immediately, it will dry and form a shell coating fast. If not using right away, cover with a wet cloth or plactic wrap.