Preheat the oven to 325°F.

Lightly spray 2 half sheet pans (13-inch by 18-inch by 1/2-inch) with non-stick cooking spray. Set aside.

In a large mixing bowl, toss together the oats, puffed rice, and pepitas. In the work carafe of a blender, blend together the coconut oil or butter, pumpkin puree, maple syrup or caro syrup, vanilla extract, cinnamon, ginger, nutmeg, and allspice on HIGH until smooth. Pour over the oat mixture, stir until evenly coated and there are no dry pockets, then divide between the two pans, pressing the mixture down evenly over the pans clear to the edges.

Bake for an hour, removing the pans every 15 minutes, and gently inserting a spatula under the granola mixture and carefully flipping it over in sections to keep some clumps in the mixture. Be sure to turn the center part over as well. Every other time, be sure to put the granola from the edges into the center and move the center toward the edges to evenly toast the mixture. After an hour, if there is still steam rising from the mixture when you stir it, you should lower the oven heat to 300°F and continue toasting it (still stirring every 15 minutes) until it feels dry to the touch or a piece left on the counter to cool is crisp when bitten into.

If you are using the optional cranberries, stir them into the granola as soon as you are done toasting it. Let the granola cool completely before transferring to jars or other containers with tight fitting lids. This granola, when properly stored, will stay good and crisp for up to three weeks at room temperature. If it starts softening, you can retoast it briefly in a low oven.