Do ahead:  Rinse the separated seeds in a colander until cold water.  Pat thoroughly dry with a cloth towel and then spread out on a fresh towel to dry overnight.  It is very important to let the seeds air dry in order to remove excess water which can create steam in the oven while cooking, preventing the seeds from crisping.

 

Pre-heat oven to 250°F. Cover a baking tray with aluminum foil.

 

In a small saucepan, melt the butter and then add in the salt, Worcestershire sauce, garlic powder, paprika and black pepper.  Add the seeds and stir well to coat.  Spread the seeds in a single layer on the baking tray and bake for 45 minutes.  Make sure to stir and toss the seeds occasionally as they bake.

 

Increase the temperature to 325°F and bake for another 5 minutes until the seeds are lightly browned and dry.  The roasted pumpkin seeds can be stored in an airtight container for up to 2 weeks.