Preheat the oven to 225°F (105°C) and line a baking sheet with parchment paper.
Melt the butter in a pan over medium heat, then add the bread slices. Cook for 1 minute on each side, or until nicely browned.
Place the bread on the baking sheet and bake for 30 minutes or until they are dry and crisp.
When the sippets are almost done, pour the milk into a pot and whisk in the cinnamon and brown sugar.
Bring to a simmer over medium heat, then add the sippets. Simmer, stirring occasionally to make sure the milk doesn’t burn, until the sippets are soft.
Add about ½ cup of the hot milk mixture to the egg yolks, whisking constantly, then add it all back to the pot and stir for 10 to 15 seconds.
Remove from the heat and serve it forth.
