Preheat the oven at 350°F (180°C). Cut the dry baguette or bread into inch-thick slices. Lay the slices down in an oven-ready dish (ceramic or glass).
In a bowl, mix a 1/2 cup (100 g) of sugar with the spices, then add in the eggs, milk, and vanilla extract. Stir until the sugar is dissolved.
Pour the mix over the slices. Wait 5 minutes for the slices to absorb some liquid, then flip the slices and wait another 5 minutes.
Place a sliver of butter on top of each slice, and sprinkle them with the remaining sugar. Bake in the oven for 15 min, then turn on the broiler and grill the top of the toast for a couple minutes, until caramelized.
Serve as is or with your favorite jam, honey, or maple syrup.