For the snowman, finely crumble pie crust. Boil pudding powder with 300 ml (approximately 1 1/4 cup) milk. Add butter and rum. Cool while stirring. Add pie crumbs and shape into a snowman. Place in a greased container and chill.
For the fondant, heat butter in a saucepan over low heat. Add lemon juice and 2 tablespoons of water. Sift in 275 grams (approximately 10 ounces) powdered sugar. Boil and stir until smooth. Remove from heat and stir in remaining powdered sugar.
Knead fondant on a powdered sugar dusted surface until cold. Color with food coloring as desired and use to coat and decorate snowman. Attach smaller pieces of fondant to fondant base with a bit of water. Decorate as desired and serve.