For the basil maple syrup: In a saucepan, bring the maple syrup and basil leaves to a simmer. Set aside to steep for 5 minutes, and then strain out the basil leaves.
For the French toast: Whisk together the cream, granulated sugar, vanilla extract and eggs in a bowl and pour into a shallow baking dish. Add the zucchini bread slices and allow to sit for 30 seconds on each side.
Heat the butter in a large pan or griddle until it begins to froth. Add the zucchini bread slices and cook until browned and caramelized, 2 to 3 minutes per side.
Divide the French toast among plates and top with confectioners' sugar. Serve with the warm basil maple syrup.