Place an oven rack on the center shelf and preheat the oven to 300 degrees F. Line a sheet pan with parchment paper or foil (if using foil, I recommend lightly spraying with cooking spray to prevent sticking).
Combine all of the ingredients in a small bowl, stirring thoroughly until the pumpkin seeds are evenly coated (taste a few and adjust the seasoning if needed). Spread in a single layer on the prepared sheet pan.
Roast for 40-50 minutes, stirring and gently flipping the seeds a few times so they cook evenly. They’re ready when the color has darkened slightly and they smell amazing. Allow to cool.
Roasted pumpkin seeds will keep in an airtight container for 2-3 days at room temperature, a week in the refrigerator, or in the freezer for around 3 months.
If you're using fresh pumpkin seeds, I recommend rinsing them first, then letting them dry out for awhile. I also pat them dry with paper towels. Anytime you're roasting (veggies, seeds, nuts, etc), it's easier to get a crunchy exterior if the food is completely dry.I melt the butter in the microwave in 10 second intervals until just melted.