Preheat oven to 240°C / 450°F (220°C fan). Position oven rack high in the oven.
Trim the ends off the zucchini. Cut medium ones into quarters lengthwise and large ones into sixths (halve, then slice into 3 long wedges).
Place zucchini on a baking tray. Drizzle with 1 tbsp olive oil, season with salt and pepper, and toss to coat.
Line up zucchini skin-side down, touching each other.
Sprinkle evenly with breadcrumbs and then with grated parmesan.
Drizzle remaining 1 tbsp olive oil over the top.
Bake for 12 minutes until the parmesan is golden and zucchini is tender but not mushy.
Serve immediately.