Preheat the oven to 350. Line 12 muffin cups with paper liners and spray them with non-stick baking spray.
In a large bowl, mix the applesauce, milk, butter, maple syrup, sugar, apple cider vinegar, vanilla, salt, cinnamon, baking powder, and baking soda together. Add the flour and mix until a batter is formed.
Fill ½ of each muffin well with the batter. Sprinkle the cinnamon and sugar for the filling on top. Then put the remaining batter on top.
In a small separate bowl, prepare your crumb topping by mixing the flour, sugar, butter, and cinnamon together. Mix until a crumble forms and add another 1 or 2 tablespoon of flour to reach a crumb consistency. Evenly distribute the crumb topping over each of the unbaked muffins.
Bake for 30 minutes or until the muffins are golden brown and cooked through the center. Option to drizzle with a little icing and enjoy warm or cool!