Adjust oven rack to middle position and heat oven to 375 degrees. Toss oats, oil, and salt together in large bowl; spread out over 12 by 18-inch baking sheet and bake, stirring often, until pale gold, 20 to 25 minutes.
While oats are toasting, heat honey and brown sugar in small saucepan over medium heat, stirring frequently, until sugar is fully dissolved, about 5 minutes. Stir in vanilla and cinnamon (if using) and set aside.
Remove oats from oven and lower oven temperature to 300 degrees. Transfer toasted oats to large bowl and toss with honey mixture until evenly coated. Stir in nuts, dried figs, and crystallized ginger.
Line 12 by 18-inch baking sheet with aluminum foil, then coat lightly with vegetable oil spray. Spread oat mixture out on prepared pan, then pack tightly into even layer using wet metal spatula. Bake until golden, 35 to 40 minutes.
Let cool on wire rack for 15 minutes, then cut into 2 by 3-inch bars in pan. Let cool completely before removing from pan.
NOTE: Quick-cooking oats cannot be substituted for the old-fashioned oats here because their texture becomes too sandy when toasted. The bars can be wrapped tightly in plastic wrap and stored at room temperature for up to 2 weeks.