Heat the vegetable oil in a skillet over medium heat, and cook and stir the pumpkin seeds until they have browned, about 10 minutes.
Transfer into a bowl, and mix with cinnamon and cayenne pepper. Set aside. Butter a jellyroll pan, and set aside near the stove.
Combine the sugar and beer in a 2-quart saucepan over medium heat. Stir until the mixture boils and the sugar has dissolved. Continue to cook, stirring frequently, until the temperature measured by a candy thermometer reaches 300 degrees F (150 degrees C), about 40 minutes. When the candy reaches the correct temperature (hard crack) it will form brittle strings when dripped into ice water.
Remove the candy from the heat, and quickly stir in the pumpkin seeds.
Pour the candy carefully into the prepared jellyroll pan to form a thin layer; allow to cool. Break the candy into bite-size pieces once cool. Store in an airtight container.
