Coffee Cake Muffins Recipe

Name: Coffee Cake Muffins Recipe
Ingredients: For the Streusel:; 1/2 cup (5 ounces) all-purpose flour; 1/2 cup (4 ounces) dark brown sugar; 4 tablespoons butter, at room temperature; 1 teaspoon ground cinnamon; For the Muffins:; 2 1/4 cups (about 11 1/2 ounces) all-purpose flour; 2 teaspoons baking powder; 1/2 teaspoon baking soda; pinch of salt; 5 tablespoons butter, at room temperature; 1/3 cup vegetable oil; 1 cup sugar; 2 eggs; 1 cup sour cream