Clarke is credited with expanding the Klondike bar from its origins as a local dessert, eaten in parts of Ohio and Western Pennsylvania, into a popular, national ice cream brand.
[1] In 1976, Clarke purchased the rights to the Klondike bar, frozen vanilla ice cream square which had been manufactured and sold by the Isaly's restaurant chain since the 1930s.
[1][2] Under Clarke, sales of the Klondike bar increased from $800,000 annually at the time of the acquisition by Clabir to more than $60 million.
[1] In 1989, after he had sold Klondike due to a corporate hostile take over, Clarke entered the British ice cream market.
[2] Clarke also moved into direct competition with Häagen-Dazs by introducing super premium ice cream and marketing Lyons Maid products at high-profile venues, such as Wimbledon.