2. Sift the first four ingredients into a large bowl.
3. Add the egg, fruit cocktail, and vanilla and mix well.
4. Pour into an 8 x 12-inch buttered and floured cake pan.
5. Mix the brown sugar, butter and walnuts together, and then sprinkle over the top of the cake batter.
6. Bake until the cake starts to pull away from the sides of the pan and a toothpick inserted in the center of the cake comes out clean, about 45 minutes.
7. Cool. Serve from the pan.
Andrea Reusing is the creator of the restaurant Lantern in Chapel Hill, N.C., and author of the book Cooking in the Moment: A Year of Seasonal Recipes. In this installment of The Key 3, she shares with Lynne Rossetto Kasper the techniques behind three of her favorite recipes: Turnip Soup, Overnight Braised Short Ribs and Tomato Salad.