Prepare zucchini and flowers: Detach zucchini flowers from the courgettes, remove pistils and peduncles, tear each flower into 2-3 parts. Trim the courgettes and slice them thinly.
Make the egg mixture: In a bowl, beat the eggs with salt, pepper, grated cheese, chopped basil, and a drizzle of olive oil.
Combine ingredients: Add the sliced courgettes and most of the torn flowers (reserve some for topping) to the egg mixture and mix well.
Prepare the baking pan: Wet and crumple a sheet of baking paper, then spread it on a baking tray. Drizzle olive oil and brush it evenly.
Bake the frittata: Pour the egg mixture into the prepared pan and spread evenly. Arrange the reserved flower petals on top, drizzle with olive oil and sprinkle a little pepper.
Cooking: Bake in a preheated oven at 180°C (356°F) on the middle shelf for 35 minutes. For extra browning, move to the top shelf for the last few minutes if desired.
Serve: Remove from oven when golden and inviting. Let cool slightly, then slice and serve.