Preheat oven to 325°. Toss pecans, almonds, coconut, pumpkin seeds, oats, salt, and oil on a rimmed baking sheet and bake, tossing once, until coconut is golden and mixture is fragrant, 10–12 minutes. Let cool. Whisk egg whites in a large bowl until foamy. Gradually add sugar, whisking until mixture is thick and opaque. Add nut mixture and fold to coat evenly. Drop ¼-cupfuls of mixture onto a parchment-lined baking sheet, spacing evenly. Bake cookies, rotating baking sheet halfway through, until edges are golden, 15–20 minutes. Transfer to a wire rack and let cool.