Preheat oven to 350°Fahrenheit. Lightly grease or line 24 muffin cups with paper baking cups. Set aside.
Beat cake mix, pudding mix, milk, oil, eggs, cinnamon and vanilla in bowl of electric mixer on low speed just to moisten, scraping sides as needed. Beat on medium speed 2-3 minutes.
In a separate bowl, combine the sugar, cinnamon and walnuts.
Spoon a bit of batter into prepared muffin cups and sprinkle with 1 teaspoon streusel. Then put on another scoop of batter and another spoonful of streusel.
Bake for 20 minutes, or until a toothpick inserted into the center comes out clean.
Allow the muffins to cool for 10 minutes.
In a small bowl, combine the powdered sugar and milk. It should be the consistency that allows you to drizzle it with a spoon over all of the muffins.
Drizzle the glaze over the muffins.
Store in an airtight container at room temperature.
Notes
The calories shown are based on the recipe making 24 muffins, with 1 serving being 1 muffin. Since different brands of ingredients have different nutritional information, the calories shown are just an estimate. **We are not dietitians and recommend you seek a nutritionist for exact nutritional information. The information in the nutrition box are calculated through a program and there is room for error. If you need an accurate count, I recommend running the ingredients through your favorite nutrition calculator.**