Preheat your oven to 350℉.
In a large bowl, add the eggs, milk, cream, vanilla, cinnamon and salt. Whisk to combine. Add the cubed challah and ensure it's all coated and has absorbed some of the liquid mixture, but is not soggy. Then gently fold in the blueberries.
In a well greased/lined cupcake pan, spoon about ⅓ cup of the French toast mixture into each cup.
Bake until golden brown - about 45 minutes.
Serve warm with maple syrup, powdered sugar, whipped cream, fruit, however you'd like!