Preheat your oven to 200°F (keep it on low) and place a baking sheet inside. You'll use this to keep finished French toast warm while you cook the rest. This takes 3 minutes.

In a shallow bowl or wide plate, crack 3 large eggs and whisk them for 30 seconds with a fork or whisk until combined. Do not over-whisk; you want some air in the mixture but not a foam.

Add 1/2 cup whole milk, 1/4 cup pure maple syrup, 2 teaspoons vanilla extract, 2 teaspoons ground cinnamon, 1/4 teaspoon nutmeg, and 1/4 teaspoon salt to the bowl. Whisk vigorously for 1–2 minutes until fully blended and smooth. The mixture should smell distinctly of maple and cinnamon. Checkpoint: You are ready to move on when the custard is uniform with no streaks of egg white visible.

Place a large nonstick skillet or griddle on your stovetop over medium-high heat. Let it heat for 2–3 minutes until a drop of water sizzles immediately on contact (this means it's hot enough). If you don't have a nonstick pan, use a cast-iron skillet for best results.

Add 1 tablespoon unsalted butter to the center of the hot skillet and swirl for 30 seconds to coat the entire surface evenly. The butter should foam and smell nutty, but not brown. Checkpoint: You are ready to move on when the butter is melted and the pan smells toasted.

Take your first slice of brioche or challah bread (ideally 1–2 days old), hold it with both hands, and dip it into the custard bowl for exactly 1 second. Flip it and dip the other side for 1 second. The bread should be wet but not soaked through (if it's soggy, you've dipped too long). Checkpoint: Both sides of the bread should glisten but not drip custard.

Immediately place the coated slice onto the hot buttered skillet. If cooking multiple slices, repeat the dipping process with 2–3 more slices and place them on the skillet without overlapping. Work quickly so the custard doesn't drain off the bread.

Let the first side cook undisturbed for 3–4 minutes. You'll know it's ready to flip when the edges look crispy and golden brown, and if you gently lift a corner with a spatula, the underside should be deep golden with a caramelized crust. Do not flip early.

Using a thin spatula, gently slide it under one slice and flip it in one smooth motion. Cook the second side for 2–3 minutes until it matches the first side in color—golden brown all over with slight caramelization at the edges.

Transfer the cooked French toast to the warm baking sheet in the preheated 200°F oven. This keeps it warm and crispy while you finish cooking the remaining bread.

Repeat Steps 5–10 with the remaining bread slices, adding 1 tablespoon butter to the skillet for each new batch. If your skillet cools between batches, heat it for 30 seconds before adding butter.

Once all slices are cooked, remove them from the oven and arrange on serving plates. Dust the top of each slice generously with powdered sugar using a fine-mesh sieve (this creates an even, light coating).

Drizzle each portion with warm maple syrup—about 2–3 tablespoons per serving. You can warm the syrup in a small saucepan over low heat for 1–2 minutes, or use it at room temperature.

Serve immediately while still warm. Add a dollop of whipped cream, fresh berries (raspberries, strawberries, or blueberries all work), or a pat of butter on top if desired.