Preheat your oven to 400°F (200°C). Line a rimmed baking pan with parchment paper or a Silpat baking mat.
Prepare the Brussels sprouts by trimming the ends and slicing each one lengthwise in half. Remove any damaged outer leaves.
Rinse the sprouts and pat them dry with a towel.
In a medium mixing bowl, combine the balsamic vinegar, maple syrup, white miso, and garlic powder. Whisk until smooth.
Add the prepared Brussels sprouts to the bowl and toss well to coat.
Spread the sprouts in a single layer on the lined baking pan, drizzling leftover marinade over the top.
Roast for 15 minutes, then remove from oven and gently stir.
Return to oven and roast for an additional 10 to 15 minutes, or until desired tenderness.
Top with dried cranberries and pecans before serving if desired.