Remove the crusts from the bread and press the slices into the cups of a muffin pan. Brush well with melted butter.
Beat the eggs well in a medium mixing bowl. Stir in the milk. Add the onion, zucchini, cheese, breadcrumbs basil, and salt and pepper to taste. Mix well.
Carefully spoon the egg mixture into the bread cases. Sprinkle with the paprika and Parmesan cheese. Place the pan in the oven and bake for about 45 minutes OR until set and golden. Keep a close eye on it.
Turn off the oven, but leave the toasts to cool for 10 minutes before transferring them to a serving platter. Garnish each with a fresh basil leaf before serving.