Streusel-Topped Muffins

Ingredients

• ✓ 2 cups all-purpose flour
• ✓ ½ cup white sugar
• ✓ 3 teaspoons baking powder
• ✓ ½ teaspoon salt
• ✓ ¾ cup milk
• ✓ ⅓ cup vegetable oil
• ✓ 1 egg
• ✓ ¼ cup packed brown sugar
• ✓ 1 tablespoon butter, softened
• ✓ ½ teaspoon ground cinnamon
• ✓ ¼ cup chopped walnuts