Walnut Cinnamon Coffeecake
["1/2 c. walnuts, chopped", "2 Tbsp. brown sugar", "1 tsp. cinnamon", "2 c. all-purpose flour", "1/2 c. sugar", "1/2 tsp. salt", "1 1/2 tsp. baking powder", "1/2 tsp. baking soda", "1/2 c. vegetable oil", "3/4 c. buttermilk", "1 egg, lightly beaten", "1 tsp. vanilla"]
["Heat oven to 350\u00b0.", "Lightly oil 8-inch square pan.", "Combine walnuts, brown sugar and cinnamon in small bowl; set aside. Combine flour, sugar, salt, baking powder and soda in another bowl and mix to blend.", "Combine oil, buttermilk, egg and vanilla in third bowl.", "Then add to dry ingredients.", "Stir just to combine. Do not overmix."]
["walnuts", "brown sugar", "cinnamon", "flour", "sugar", "salt", "baking powder", "baking soda", "vegetable oil", "buttermilk", "egg", "vanilla"]