Make the bread pudding
In a large bowl, combine the sugar, eggs, cocoa, and vanilla and whisk until smooth. Add the milk, nutmeg, and cinnamon and continue whisking to combine. Stir in the bread, mix well, and set aside for the bread to soften, about 30 minutes.
The bread should soak up nearly all of the custard. Occasionally stir the bowl from the bottom to evenly distribute the custard.