Preheat your oven to 425°F (220°C).
Wash and dry the zucchinis, then cut them in half lengthwise.
In a bowl, combine olive oil, garlic powder, salt, and pepper.
Brush the mixture evenly over the zucchini halves.
Place the zucchini cut-side down on a baking sheet lined with parchment paper.
Roast in the preheated oven for about 15 minutes.
Flip the zucchini over and roast for an additional 10 minutes.
Check for doneness; they should be tender and lightly browned.
Remove from the oven and garnish with fresh herbs or cheese if using.