Put on a pot of coffee and enjoy these delicious muffins. They make a wonderful breakfast or brunch muffin. The muffins freeze very well, IF you have any left overs. I hope you enjoy them as much as we do. :)
Line a muffin pan with muffin cups, or spray pan with a non-stick cooking spray.
In a small bowl mix the crumble topping ingredients together. Use a pastry blender or a fork, and blend until mixture is crumbly; set aside.
In a mixing bowl, cream together the butter, sugar, vanilla, and salt until thoroughly combined, about 3 minutes. Beat in eggs and mix for another 2 minutes or so. Add the flour, baking powder, cinnamon, and milk; mixing just until dry ingredients are combined. Stir in the apples and walnuts.
Spoon mixture into prepared muffin pan. Sprinkle tops with crumble topping.
Bake for 30 minutes, or until toothpick inserted in center comes out clean. Remove and cool on wire rack.