01 -  Preheat oven to 425°F. Line a baking sheet with parchment paper. 
 02 -  In a large mixing bowl, whisk together maple syrup, Dijon mustard, olive oil, apple cider vinegar, sea salt, and black pepper until the mixture is thoroughly emulsified. 
 03 -  Add the trimmed and halved Brussels sprouts to the bowl and gently toss until each piece is evenly coated with the glaze. 
 04 -  Distribute the glazed Brussels sprouts cut side down in a single layer on the prepared baking sheet for optimal browning. 
 05 -  Roast for 20 to 25 minutes, stirring halfway through, until the Brussels sprouts develop a golden, caramelized finish and crisp edges. 
 06 -  Transfer the roasted Brussels sprouts to a serving dish. Garnish with chopped toasted pecans and fresh parsley if desired. Serve immediately while hot.