Add two sleeves of saltines to a one-gallon zip-top bag. (More than that, and there's little room to toss the crackers with the oil and spices.)
Add half the olive oil to the bag, seal and toss the crackers gently to coat. Add the rest of the olive oil and repeat.
Mix the dry ingredients in a bowl, then add half of the dry mixture to the oil-soaked saltines. Seal the zip-top bag and toss gently. Add the remaining dry mixture and repeat.
Let the bag sit for several hours or overnight. (It helps to flip the bag occasionally during this period.)
Preheat oven to 250 F. Remove crackers from bag and place in a single layer on a rack in a baking sheet. Bake for 15 minutes.
Recipe adapted from Southern Living.