Preheat the oven to 300 degrees. In a medium sauce pan combine the pumpkin, brown sugar, oil, honey, vanilla, pumpkin pie spice, and salt. Stir and cook over medium-low heat for 3-5 minutes, or until heated through and the sugar has dissolved.
In a large bowl, combine the dry oats, sunflower seeds, and pumpkin mixture. Stir very well until the oats are evenly coated with pumpkin and there are no dry oats left on the bottom of the bowl.
Spread the oat mixture over one or two baking sheets covered with parchment paper. Bake the oats in the preheated oven for 45-60 minutes, or until they are mostly dry. Stir the oats once at 30 minutes, and again at 45 minutes. The amount of time needed to bake the granola will depend on how thick they are piled onto the baking sheet. If using one baking sheet it will take about an hour, if they're spread between two sheets, it will take about 45 minutes.
Once the oats are finished cooking, sprinkle in the chopped cranberries, stir, then press and pack the mixture down onto the baking sheet to cool. Packing it down before it cools helps solidify the granola and create chunks rather than individual flakes. Once cool, store in an air-tight container for up to a week.
If you can't find pumpkin pie spice blend at your local supermarket, it can be made with a simple blend of individual spices using this recipe.