Preheat the oven to 325°F. Place 2 cups raw hull-on pumpkin seeds under cool running water around 60°F for 2 to 3 minutes. Rub handfuls gently between your fingers and pull away every visible strand of orange pumpkin pulp. Then move the seeds through the water several times so loose fibers float away. Don't crush or split the pale shells because damaged seeds roast faster than intact ones. The seeds should look clean and pale cream with no slippery orange strands clinging between them. They'll still feel wet but they shouldn't feel slimy. If pulp remains, it can darken before the shells crisp and leave bitter spots. Rinse thoroughly now because clean shells toast more evenly later.

Spread the rinsed seeds into a thin uneven layer at about 70°F room temperature. Press and blot them firmly for 1 to 2 minutes and then leave them exposed for 15 to 20 minutes. Turn several handfuls midway so moisture trapped beneath overlapping shells can escape. Keep the layer loose instead of piling the seeds because crowded wet shells hold water between them. The seeds are dry enough when the pale shells change from glossy to mostly matte and no visible droplets remain. Pick up a handful and release it. The seeds should separate easily instead of sticking together. Leave them wet and they'll steam during roasting instead of turning crisp. Drying first lets surface moisture escape before oil seals the shells.

Keep the dried seeds near 70°F and coat all 2 cups with 1 tablespoon extra-virgin olive oil. Add 3/4 teaspoon kosher salt and 1/2 teaspoon freshly ground black pepper. Toss for about 60 to 90 seconds while lifting seeds from the bottom and folding them over the top. Stop once the oil forms a thin sheen instead of collecting underneath. The pale shells should look lightly glossy with uneven black pepper flecks and tiny salt crystals across their surfaces. Some seeds will carry more pepper than others and that's natural. Too much oil leaves puddles and makes the shells heavy rather than crisp. Use a thin coating because excess fat slows surface dehydration during roasting.

Spread the seasoned seeds into one loose layer and roast at 325°F for 20 to 25 minutes. At minute 10, move the seeds from the darker edges toward the center and redistribute the center seeds outward. Continue roasting until most shells deepen to golden amber. Then remove them and cool for 10 minutes before serving. (I tested a hotter oven first, the edges darkened before the centers became crisp.) You'll smell a warm nutty aroma around minute 18 and hear a faint dry rustle when the seeds move. Their shells should look golden with scattered deeper brown patches and distinct black pepper flecks. Go past deep amber and the thin shells can taste bitter. Roasted Pumpkin Seeds with Salt and Pepper crisp further as they cool. Moderate heat browns the shells without scorching their delicate edges.