Lightly coat a grill pan with cooking spray; heat grill pan over medium heat. Add avocado halves and pineapple slices; cook for 6 to 8 minutes or until heated through and golden grill marks appear, turning once. Finely chop pineapple.
In a heavy resealable plastic bag place avocados, pineapple, sour cream, cilantro, lime juice, chipotle pepper, and salt; seal bag. Knead bag with your hands to combine ingredients.
Chill for up to 8 hours. Serve guacamole with tortilla chips.