Scoop the seeds from the pumpkin or winter squash and place in a bowl of water to separate the seeds from the flesh (the seeds will float). Rinse in a colander to remove excess flesh from the seeds. Lay the seeds in a single layer on a kitchen towel to dry.

Preheat the oven to 300°F and line a baking sheet with parchment paper. Place the seeds in a small bowl and drizzle with the olive oil and salt and toss to coat. Spread in a single layer on the baking sheet and roast for 35 to 45 minutes, stirring halfway, until golden brown and crisp.

Toss with a few sprinkles of chili powder and serve.