Mix the maple syrup, oil and light brown sugar in a large microwave-safe bowl and microwave until the sugar has dissolved.
Combine the dry ingredients with the wet ones and spread the granola over 3 full sheet trays.
Bake the granola in batches, mixing occasionally to insure even baking, until dry and light, 20 to 30 minutes. Carefully mix in the raisins and currants and bake until golden brown, about 20 minutes more. Mix the granola one final time after it is removed from the oven.