Preheat oven to 350°. Spray a 13×9-inch baking pan with baking spray with flour. Line with parchment paper, letting excess extend over sides of pan; spray again.
For cake:
In a large bowl, whisk together flour and pie spice. In another large bowl, beat soup, sugars, shortening, eggs, and milk with a mixer at medium-low speed until fully combined. Add flour mixture, beating on low speed just until combined. Fold in raisins, if using. Pour batter into prepared pan.
Bake until a wooden pick inserted in center comes out clean, about 30 minutes. Let cake cool completely in pan. Using the excess parchment as handles, remove cake from pan and place on a serving platter.
For frosting:
In a large mixing bowl, beat egg whites with a mixer at medium-high speed until stiff peaks form. Slowly add corn syrup while beating, continuing to beat until smooth and glossy, about 2 minutes. Beat in vanilla just until combined. Spread frosting onto cooled cake.
Notes
Try your hand at baking this oh-so-easy cake, and you’ll see for yourself why this one-of-a-kind cake has stood the test of time.
*We used Campbell’s.
Recipe by Taste of the South at https://tasteofthesouthmagazine.com/tomato-soup-cake/