Preheat the oven to 400°F (200°C) and grease a loaf pan with oil. Set aside.
Sauté diced zucchini in a large frying pan with one tablespoon of olive oil, until slightly golden.
Transfer to a plate lined with paper towel and pat-dry.In a large bowl, mix together all-purpose flour, baking powder, eggs, olive oil, basil pesto and warm milk. Season with salt and pepper.
Add diced zucchini, goat cheese, grated cheese and stir. If using, add a few basil leaves to the batter and stir.
Pour the batter into the pan and bake for 45 minutes or until a toothpick inserted in the center comes out clean.