The chocolate cake passed through a metal detector and was sitting on a table when it was attacked.
Cake and frosting went flying when a Cowlitz County sheriff's deputy grabbed the cake molester and took him to the ground. A local newspaper says more deputies rushed to help Tuesday, only to end up smeared with frosting.
Deputy Joe Connor told a local television station that 50-year-old Robert Fredrickson was arrested for investigation of third-degree theft. The Daily News says the man had been on his way to a court appearance.
A local grocery offered to replace the cake.