Preheat your oven to 425°F and line a large sheet pan with parchment paper. Position the oven rack to the middle position—this ensures even heat circulation around the vegetables without burning the bottom.

Trim brussels sprouts by removing yellowed outer leaves and slicing them in half lengthwise, keeping the flat side facing down for roasting. Rinse and pat completely dry; moisture prevents proper caramelization and creates steam instead of browning.

Combine olive oil, garlic powder, onion powder, salt, and pepper in a small bowl, whisking until the dried spices fully dissolve into the oil. Arrange halved sprouts cut-side down on the prepared pan, then drizzle the oil mixture evenly, tossing gently to coat all surfaces.

Roast for 18-20 minutes until the flat sides turn deep golden-brown and the outer leaves crisp noticeably. The beautiful sheet pan brussels sprouts recipe relies on this initial roasting phase to build that crucial texture foundation.

While sprouts roast, whisk together balsamic vinegar, maple syrup, Dijon mustard, and minced garlic in another small bowl until combined smoothly. This glaze requires no cooking—the oven's heat will caramelize it onto the vegetables.

Remove the pan and drizzle the glaze evenly over all sprouts, then sprinkle Parmesan cheese and fresh thyme across the top. Return to the oven for 5-7 minutes until the cheese melts and the glaze becomes sticky and reduced.

Cool for 2-3 minutes before serving, allowing the glaze to set slightly so it adheres to each piece rather than pooling on the pan.