Apple Streusel Muffins

I got this from TOH's Quick Cooking Magazine. My family loved these.

• Ready In: 45 mins
• Yields: 6 muffins

Ingredients

• 1 (6 1/2ounce) box  apple cinnamon muffin mix (I used Betty Crocker's)
• 1  large tart apple, peeled and diced
• 1⁄3 cup  chopped walnuts
• 3  tablespoons brown sugar
• 4 1⁄2 teaspoons all-purpose flour
• 1  tablespoon butter or 1  tablespoon margarine, melted

• Glaze

• 3⁄4 cup powdered sugar
• 1⁄2 teaspoon vanilla extract
• 1 -2  tablespoon milk

Directions

1. Perpare muffin mix according to package directions; fold in apple.
2. Fill greased muffin cups three-fourths full.
3. In a small bowl, combine the walnuts, brown sugar, flour and butter; sprinkle over batter.
4. Bake at 400 degrees for 15-20 minutes or until tests done.
5. Cool for 5 minutes before removing from pan to a wire rack.
6. Combine the glaze ingredients; drizzle over warm muffins.