Slice the bread and cut it into 1-inch cubes. Put it in a large bowl and toss it with the cinnamon.
Make the custard by whisking the eggs, sugar, cream, milk, and vanilla together until well combined. Pour the custard over the bread. Cover and refrigerate for at least 4 hours and up to 24 hours.
Preheat the oven to 325°. Line a standard-size 12-cup muffin tin with paper liners, or generously grease with butter.
Scoop a heaping 1/2 cup of the bread pudding mixture into each of the 12 muffin cups; each one should be nicely mounded. Top off each bread pudding with any remaining custard.
Bake for 45 minutes, rotating the muffin tin halfway through the baking time. The bread puddings should be lightly golden brown on top. Dust them with confectioners’ sugar while they’re still warm.
Serve immediately