In a small bowl, combine the flour, sugar, baking powder, baking soda, cinnamon and salt. In another bowl, mix the egg, milk, and oil. Add the dry ingredients into the wet ingredients and mix just until combined. Do not overmix!
For the streusel, combine the flour, cinnamon, sugar and walnuts together. Cut in the softened butter until you have a crumbly mix and the butter is all mixed in.
Spray jumbo muffin tins with cooking spray and spoon a heaping tablespoon of batter into the bottom of each cup. Put a tablespoon of apple butter over top the batter. Then sprinkle some streusel topping over the apple butter. Distribute the remaining muffin batter over each of the muffin cups equally. Sprinkle the remaining streusel evenly over top the muffins.
Bake at 425º Fahrenheit for 5 minutes, then reduce the oven temperature to 375º Fahrenheit and cook for an additional 13-15 minutes. The muffins are done when a toothpick inserted into the center comes out clean.
Mix the powdered sugar and apple cider together until smooth, then drizzle with a spoon over top the muffins.
Store in an airtight container at room temperature.
You can make these in standard size muffin tins, just reduce the baking time.The calories shown are based on the recipe making 6 jumbo muffins, with 1 serving being 1 muffin. Since different brands of ingredients have different nutritional information, the calories shown are just an estimate.