8 (1-inch-thick) slices challah or brioche, 6 large eggs, 4 tablespoons (50g) sugar, plus more for sprinkling (see note above), 1 tablespoon (15ml) rum, 1/2 loosely packed teaspoon (2g) grated zest from 1/2 medium orange, 1/4 teaspoon (1ml) vanilla extract, Pinch kosher salt, Pinch ground cinnamon, Pinch freshly grated nutmeg, Pinch freshly grated star anise (optional), 2 cups (480ml) whole milk, 4 tablespoons (56g) unsalted butter for the pan, plus more as needed, 1/2 cup (120ml) crème fraîche, Maple syrup, for serving
- Set a wire rack on a rimmed baking sheet in the oven and preheat to 250°F. If using fresh bread, arrange slices in a single layer on rack and cook in oven, turning once, until lightly toasted, about 20 minutes. (If the bread is stale, you can skip this toasting step.)
- Meanwhile, in a large mixing bowl, whisk together eggs, sugar, rum, orange zest, vanilla extract, salt, cinnamon, nutmeg, and star anise (if using) until thoroughly combined. Add milk and whisk to blend.
- In a stand mixer fitted with the whisk attachment, or in a medium bowl with either an electric mixer or a whisk, beat crème fraîche until soft peaks form. Set aside.
- Heat 2 tablespoons butter in a large nonstick or cast iron skillet over medium heat, swirling skillet, until foaming subsides. Meanwhile, soak 2 to 3 slices of bread in egg bath, turning, until saturated. Add soaked bread to skillet and cook, swirling occasionally, until browned on bottom side, about 3 minutes. Sprinkle top side of bread with sugar, flip, and continue to cook, swirling occasionally, until browned on second side, about 3 minutes longer. Transfer French toast to rack in oven in a single layer to keep warm and repeat with remaining slices of bread and egg bath. Allow each batch of French toast to heat in oven for at least 10 minutes (but not more than 30) to ensure it is fully cooked through.
- Serve French toast with whipped cream and maple syrup.