There is no single frosting amount that fits every house-shaped cake. A lightly frosted cake needs far less than one covered in snowdrifts, roof piping, and candy details.
Decide how much surface you will cover
Will frosting cover the entire cake or only the roof, windows, and trim? That decision changes the amount more than almost anything else.
Plan for kids to use more
Children tend to spread generously and experiment. If several kids are decorating, a little extra frosting can keep the activity relaxed.
Separate colors before decorating
If you want white snow plus red or green details, portion frosting before everyone starts. That protects the base color and makes the table easier to manage.
Use the decorations to do some work
With The Tomte Cake, frosting does not have to create every detail. Candy, powdered sugar, cereal, and other toppings can add texture and color while keeping the frosting job simple.
For Tomte Cake baking, use the official recipe as your primary guide and let the family fun build around it.