Complex sentence: During the 1960s a solid version of the confection formula was created from Pixy Stix named SweeTarts and grew in popularity with other hard packed candies, which caused Pixy Stix to become almost extinct.
Split into simpler sentences: During the 1960s a solid version of the confection named SweeTarts was created from Pixy Stix. It grew in popularity with other hard-packed candies, which caused Pixy Stix to become almost extinct.