Knäck is a Swedish toffee prepared with caramelized sugar and butter or heavy cream. It is often additionally sweetened with syrups and may be enriched with various chopped nuts. The caramelized mixture is usually left to set in miniature paper molds, or it can be cut into bite-sized pieces.

The name of this Christmas staple name translates as crack or break, referring to the typically crispy texture of toffee.