Split two of the eggs into yolks and whites. Put the two yolks, along with the other two yolks, into small ramekins.
Put the egg whites into a shallow bowl and add the other two eggs. Add in the milk, sugar, spices, and salt and whisk to combine.
Cut the brioche carefully into 4 separate 2 to 3 inch cubes. I stared this by trimming the crusts, then sectioning it into 4 pieces. Then I kept trimming until I ended up with the cubes. Then use a pairing knife to remove a square from the center of the cube. (refer to photos above for help)
One by one, dip the cube into the egg mixture to coat all sides. It will become fragile at this point, so be gentle! Place it onto a work surface and add more egg mixture to the center. The inside needs to be fully coated because it will help the yolk not break.
Add an egg yolk into the center of the bread. Take the small square that you cut out of the bread and squish it slightly to make sure there is space for the egg yolk in the center of the bread, then dip the square into the egg mixture to coat on all sides. Return the square to the place in the bread cube where you cut it out, sealing the yolk in the center of the bread. Repeat with the remaining bread cubes.
Preheat a nonstick pan to medium high heat and add some butter. Put a spatula upside-down on top of the bread cube and gently flip it so it is resting on the spatula with the side of the bread that has the opening facing downward. Slide the bread into the pan and cook that side first to really make sure the yolk is sealed into the bread. Repeat with the remaining bread cubes. Turn the heat down to medium low.
gently rotate the bread cubes every few minutes to cook on all sides and get a nice brown color.
Transfer the breads to plates and serve with butter and syrup