1. place about a cup of torn bread into each muffin cup. whisk milk, eggs, sugar, vanilla, and cinnamon until combined. slowly and carefully pour over the cubes bread. cover with plastic wrap and refrigerate for 2 hours or up to overnight.
2. preheat oven to 350 degrees Fahrenheit.
3. while oven is preheating, make streusel topping. mix butter, brown sugar. flour, cinnamon, and salt, then sprinkle over muffins. bake for 25 minutes. let cool slightly before serving. serve warm with maple syrup.