Preheat oven to 425°. Place crusts on ungreased baking sheets; brush with oil. Combine pumpkin, minced chipotle peppers, salt and pepper; spread over crusts. Combine chicken and salsa; spoon over pumpkin layer. Top with cheese and red onion.
Bake until edges are lightly browned and cheese is melted, 12-15 minutes. Let stand 5 minutes before cutting. If desired, sprinkle with cilantro.