Preheat oven to 425° F; cover a baking sheet with tin foil or parchment paper (optional but makes for easier cleanup.)
Cut the broccoli into bite-sized florets. In a colander, rinse them off and give them a good shake to dry them off; transfer them to a large bowl.
Drizzle the florets with the olive oil and sprinkle them with 2 TBSP of nutritional yeast, followed by the garlic salt. With a large spoon, give the broccoli a good toss in order to evenly coat the florets. You could also cover the bowl and shake the contents until evenly coated. When done, spread the florets out onto a baking sheet. Sprinkle the rest of the nutritional yeast over the broccoli florets.
Bake in the oven for 15-20 minutes, tossing the broccoli halfway through.
Season with a bit of extra garlic salt if needed, and cracked black pepper if desired.