Toss pumpkin seeds with paprika, Cajun seasoning, and salt until coated. Mix Worcestershire sauce with melted butter in a small bowl, pour over seeds, and stir to to combine. Spread seeds onto a baking sheet in a single layer.
Roast seeds in the preheated oven until browned and crunchy, 45 minutes to 1 hour; stir and turn seeds several times during roasting.
Toss a salad with these seeds, sprinkle over a chicken dish, or serve as a snack.