Preheat Oven To 450°F.
Grease A Rimmed Baking Sheet With Nonstick Spray.
In A Medium Bowl, Mash Garlic, Oil, Salt, And Pepper Together.
Add Brussels Sprouts And Toss To Coat.
Spread In A Single Layer On Baking Sheet And Roast For 8 Minutes.
(Hang On To The Bowl.
)
Remove Sprouts From Oven, Cut Each In Half With A Sharp Knife, And Toss Once Again In The Bowl To Coat Cut Side With The Remaining Oil And Seasonings In The Bowl.
Return To Pan And Roast For Another 12 Minutes, Flipping After 6 Minutes.
Top With Parmesan And Serve Immediately.