Brush the baking sheet with olive oil. Preheat a broiler.
Wash the broccoli rabe in cold water then pat it dry with a clean dish towel. Cut the floret off the stems, keeping the leaves and florets intact. (You can discard the stems.)
Place the broccoli rabe in a bowl with the olive oil, garlic powder, and kosher salt and mix until well combined. Place it on the baking sheet.
Broil 2 minutes, then remove the sheet and stir. Broil 2 minutes more until fully wilted.
Stir in the lemon juice & zest. Taste and add salt or fresh ground black pepper to taste.