Toasting the oats and almonds before soaking them gives this muesli a nuttier flavor.
Preheat oven to 350 degrees. Place oats and almonds on a rimmed baking sheet. Bake until almonds are golden brown, 7 to 8 minutes; let cool to room temperature. In a small bowl, stir together 3/4 cup of toasted oat mixture, yogurt, and milk. Cover and refrigerate until oats are soft, 1 hour or up to overnight.
Spoon muesli into two bowls. Top with apple and remaining toasted oat mixture; drizzle with honey.