Beat eggs and coquito together. Add cinnamon, nutmeg, salt, vanilla and sugar.
Dip the bread slices into the mixture, allowing each side to sit for 1-2 minutes in the eggnog mixture. You may also leave the slices in the eggnog mixture overnight if you choose to.
When ready to cook the french toast, heat a large skillet or griddle over medium heat and coat generously with butter. When the skillet is hot, cook the french toast in batches (do not overcrowd) until golden and crisp, 4 to 5 minutes per side.
Remove and serve immediately with whipped cream, crushed walnuts and maple syrup/honey.