Preheat the oven to 400ºF.
Wash and slice the Brussels sprouts. Quarter larger sprouts and halve smaller sprouts.
Toss the Brussels sprouts in 5 tbsp olive oil, plus the garlic powder, salt, and pepper. Spread in an even layer in a dark sheet pan and back for 20 minutes.
Toss the Brussels sprouts in an additional 2 tbsp olive oil, then return to the oven for 10 more minutes, until the sprouts are tender and well-charred.
Combine the agave nectar and chili garlic sauce, then drizzle over the Brussels sprouts and toss to coat. Serve!