"Always a hit and much-requested recipe. I suggest you double the recipe 'cause everyone loves it! Have made a day ahead and marinated in fridge. Have found it best to add the apples, cranberries, and walnuts in the last 5 to 7 minutes."
Combine Brussels sprouts and apple in a large bowl. Whisk together olive oil, maple syrup, and balsamic vinegar in a small bowl and pour over Brussels sprouts-apple mixture. Toss until well combined and distribute in one layer on a baking sheet. Season with salt and pepper.
Roast in the preheated oven until Brussels sprouts are tender and browned, 10 to 15 minutes, turning them after about 6 minutes. Toss with cranberries and walnuts.