Streusel Coffee Cake Muffins

from Stephanie

For topping:
3 Tbsp unsalted butter, softened
1/4 cup packed light brown sugar
1/4 cup quick or old-fashioned rolled oats
1/4 cup all-purpose flour
1/4 cup chopped walnuts
1/2 tsp ground cinnamon
1/4 tsp nutmeg

For batter:
2 cups all-purpose flour
2/3 cup packed light brown sugar
1 Tbsp baking powder
1/2 tsp baking soda
1/4 tsp salt
1 tsp ground cinnamon
1/2 tsp ground nutmeg
1 cup buttermilk
1 egg
1 tsp vanilla extract
1/2 cup unsalted butter, melted and slightly cooled

Preheat oven to 375° F. Spray 12-cup muffin pan with cooking spray and set aside.

Prepare topping: In medium bowl, combine softened butter, brown sugar, oats, flour, walnuts, cinnamon and nutmeg, stirring with fork until mixture is crumbly. Set aside.

Prepare batter: In large bowl, combine flour, brown sugar, baking powder, soda, salt, cinnamon and nutmeg. Stir until well blended.

Whisk together buttermilk, egg and vanilla. Pour into dry ingredients, followed by melted butter. Stir until evenly moistened; do not overwork.

Spoon batter evenly into prepared muffin cups. Sprinkle topping over tops. Bake until golden and toothpick inserted in center comes out clean.

Cool on wire rack 10 minutes before unmolding.