In a large bowl, combine all of your dry ingredients. In a separate bowl or measuring cup, combine oil, honey, and vanilla. Add the wet ingredients to the dry ingredients.
Stir well to coat.
Using an extra large baking sheet covered in parchment or a silpat, spread granola mixture over sheet to form a thin layer.
Bake in preheated 250 degree F oven for a total of 1 1/2 hours, stirring or flipping every 15 minutes or so.
Remove from oven and allow to fully cool, undisturbed, on baking sheet. When ready, you may break the granola up into small pieces or into large chunks if you want clusters. Store at room temperature in an airtight container.
Notes
Makes 6-8 cups. Nutritional info based on a serving size that's about 1/4 cup.