Grease a 13×9 baking dish with cooking spray. Line the pan with parchment sheets that overhang all four sides of the pan (the cooking spray will help hold the paper in place).
In a large cooking pot, stir together the butter, sugars, corn syrup, milk, cream and maple syrup. Clip a candy thermometer to the side of the pot or insert the probe of a digital thermometer into the mixture. Set the pot over medium heat and stir until the butter is melted and all ingredients are mixed. Bring the mixture to a bubble.
When the mixture is consistently bubbling, allow the candy to cook without stirring for about 20 minutes, or until the thermometer reads 248-250°F. Remove from heat and stir in the bourbon and salt. Be careful! The mixture will bubble and sputter with the bourbon addition. Stir well until the salt and bourbon are well incorporated.
Pour the mixture into the prepared dish and immediately sprinkle on the pumpkin seeds. Let cool 10 minutes and then refrigerate until firm, about 1-2 hours. Lift the firm caramel block out of the pan with the overhanging parchment. Cut into pieces and wrap individually in waxed paper squares.
Candies will keep at room temperature for up to one week. Refrigerate for longevity, about 8-10 days.
Keyword bourbon balls, butter caramels, fall, maple syrup, pumpkin seed