In a medium-size pot, combine sugar, brown sugar, corn syrup, evaporated milk, whipping cream, and butter. Monitor the heat of the mixture with a candy thermometer while stirring.
Firm ball
245-250* F
The syrup is formed into a stable ball, but loses its round shape once pressed
When the thermometer reaches 250 degrees F (120 degrees C) remove the pot from the heat.
Stir in vanilla. Transfer mixture to the prepared pan and let the mixture cool completely. When cooled cut the Carmel into small squares and wrap them in wax/parchment paper for storage.