Mix pumpkin, spice, sugar, corn syrup and evaporated milk in large pan and cook over medium heat.
Mixture will begin boiling. If it boils too close to top reduce heat slightly.
Continue cooking until mixture reaches soft ball stage (235-245 degrees). You can test for this by seeing the syrup forms a ball while in the cold water, but flattens once removed from the water.
When it reaches this stage, remove from heat.
Take butter and grease inside of glass baking dish.
Add remainder of butter and stir until mixture start to lose its? sheen.
Then pour into buttered baking dish and allow to cool.