Set bread out overnight to harden, or use stale or day-old bread. (Fresh bread will work, but stale bread will hold up against more liquid, which makes a more stable French toast).

Whisk together eggs, eggnog, cinnamon, nutmeg, and brown sugar until well combined.

Dip each side of the bread in eggnog mixture until both sides are coated.

Place soaked bread on a hot, buttered pan and cook until golden brown on each side.

Serve French toast warm with optional toppings.