When measuring flour, we spoon it into a dry measuring cup and level off the excess. (Scooping directly from the bag compacts the flour, resulting in dry baked goods.) To toast the walnuts, preheat the oven to 350 degrees F, spread the nuts in an even layer on a rimmed baking sheet and bake, shaking halfway through so they don’t burn, 8 to 12 minutes. To toast the sweetened shredded coconut, preheat the oven to 350 degrees F, spread the shredded coconut in an even layer on a rimmed baking sheet and bake, stirring the coconut every few minutes, until light golden brown, 15 to 20 minutes.