Twix advert from 1991.

Twix is a chocolate-covered chocolate bar made by Mars, Inc., consisting of a butter cookie centre topped with caramel and coated in milk chocolate. Being somewhat smaller in cross section than other candy bars, Twix are typically packaged in pairs. Twix was first produced in the UK in 1967^, and introduced in the United States in 1979.

  

Twix was called Raider in Austria, Belgium, Denmark, Finland, France, Germany, Greece, Italy, the Netherlands, Poland, Portugal, Spain, Sweden, Switzerland and Norway for many years before its name was changed in 1991 (2000 in Finland, Denmark, Norway, Sweden and Turkey) to match the international brand name.

Info taken from Wikipedia