Red Watermelon Cake 

1/2 cup shortening
1 1/2 cup sugar
2 eggs
3 tbsp. water
1 tbsp. red food color
1 tbsp. cocoa
2 1/2 cups flour
1/2 tsp. salt
1 cup buttermilk
1 tsp. soda
1 1/2 tsp. vinegar
1 cup raisins 

Cream shortening, gradually adding sugar, beating well. Add eggs, one at a time, beating well after each addition. Combine water, food color and cocoa, add to creamed mixture, beating well. Combine flour and salt, add to creamed mixture alternately with buttermilk. Combine vinegar and soda, stirring well. Stir into batter. Fold raisins into batter. Pour into 2 greased 9 inch cake pans. Bake at 350 F. For 35 to 40 minutes. Cool in pans for 10 minutes, remove and let cool completely. Spread frosting between layers and on top and sides of cake.

Frosting:

1/4 cup plus 1 tbsp. flour
1 cup sugar
1 cup evaporated milk
1 cup butter/margarine
1 tsp. vanilla
10 drops green food color 

Combine flour, sugar, milk and butter in sauce pan, cooking over medium heat, stirring constantly about 20 minutes or until thickened. Stir in vanilla and coloring. Cool and frost cake.