Preheat the oven to 300°F.

Place the oats, brown sugar, pie spice and salt in a large bowl and stir to combine.

In a small bowl, whisk together the honey, oil and vanilla. Pour over the oat mixture and mix until the oats are thoroughly coated.

Spread the mixture in a thin, even layer on a rimmed baking sheet. Bake for 15 minutes, then stir and continue baking until the granola is very light golden brown, about 10-15 minutes longer.

Place the baking sheet on a wire rack and cool the granola to room temperature, stirring occasionally, about 20 minutes. (Note: It will harden as it cools.)