Easy Apple Coffee Cake
["2 cups all purpose flour", "1 cup granulated sugar", "2 tsp baking powder", "1/4 tsp salt", "1 large egg", "1 cup milk", "2 Tbsp salad oil", "2 large apples, peeled, cored and thinly sliced", "1 cup firmly packed brown sugar", "1 tsp ground cinnamon", "1/3 cup melted butter or margarine", "1/2 cup chopped walnuts"]
["In a bowl, stir together flour, granulated sugar, baking powder and salt."]
["flour", "sugar", "baking powder", "salt", "egg", "milk", "salad oil", "apples", "brown sugar", "ground cinnamon", "butter", "walnuts"]