Place a medium saucepan over medium heat. Add pumpkin seeds and millet; cook, stirring constantly, until seeds and millet are evenly toasted and golden brown, 5 to 7 minutes.
Stir in milk, pumpkin pie spice and salt. Bring to a boil, then reduce heat to medium-low. Simmer, without stirring, until millet is tender and most milk has absorbed, about 20 minutes. Cover and let stand for 5 minutes. Drizzle with honey or agave before serving, if desired.