How to Make It
Whisk together half-and-half, orange zest, cinnamon, salt, eggs, and egg yolks in a bowl until completely combined. Arrange bread slices in a 13- x 9-inch baking dish or rimmed baking sheet. Pour egg mixture over bread. Let stand 4 minutes; turn bread slices, and let stand until egg mixture is absorbed, about 4 minutes.
Heat a large nonstick skillet over medium. Melt 2 tablespoons butter in skillet. spreading over entire surface. Arrange 4 bread slices in skillet, and cook until golden brown, 4 to 5 minutes on each side. Repeat with remaining 2 tablespoons butter and uncooked bread.
Serve French Toast drizzled with warm maple syrup and dusted with powdered sugar.