Preheat the oven to 400°F (200°C).

Toss the halved Brussels sprouts with olive oil, salt, and pepper on a baking sheet.

Roast the Brussels sprouts in the preheated oven for 20-25 minutes, or until they're tender and slightly caramelized.

While the sprouts are roasting, in a saucepan over medium heat, combine the apple cider and maple syrup. Simmer until it's reduced by half, creating a thick glaze (about 5-7 minutes).

Once reduced, add the butter to the cider reduction and stir until melted and well combined.

Remove the Brussels sprouts from the oven and drizzle the cider glaze over the roasted sprouts, ensuring they're evenly coated.

Return the baking sheet to the oven for an additional 5 minutes to let the glaze caramelize slightly.

Serve the Cider-Glazed Brussels Sprouts hot, and if desired, garnish with the almonds and a drizzle of additional glaze.