Beat powdered sugar, egg whites, and vanilla into a thick, glossy icing.

Break graham crackers into wall, roof, and end panel shapes.

Pipe icing along edges and assemble the walls on a cardboard base.

Attach the front and back triangle panels.

Pipe icing along the top edges and attach the roof panels.

Let the structure set for about 10 minutes.

Pipe icing snow and press on candies to decorate.