Name: Orange Walnut Oat Bran Muffins
Ingredients: 1 cup oat bran; 1 cup buttermilk (shaken); 1/4 cup sour cream (or Greek yogurt); 3 Tbsp fresh orange juice; zest of 1 orange; 1/2 tsp orange extract; 4 tablespoons unsalted butter, at room temperature; 1/2 cup light brown sugar, packed; 2 extra-large eggs, at room temperature; 1 cup all-purpose flour; 1/2 cup oat flour; 3/4 teaspoon baking powder; 1/2 teaspoon baking soda; 1/2 teaspoon salt; 1/2 cup chopped walnuts; rolled oats and sugar for sprinkling