1 (8 oz.) carton sour cream
1/4 c. milk
1 c. butter (no substitute), softened
1 1/2 c. white sugar
1 c. (packed) brown sugar
4 eggs, separated
2 3/4 c. flour
2 tsp. baking powder
1/2 tsp. salt
1 tsp. vanilla flavoring
1 tsp. rum flavoring
Caramel Frosting

Combine sour cream and milk, set aside. Cream butter and gradually add sugars, beating well at medium speed of electric mixer. Add egg yolks, one at a time, beating well after each.

Combine flour, baking powder and salt; add to creamed mixture alternately with sour cream mixture, beginning and ending with flour. Mix after each addition. Add flavorings. Beat egg whites until stiff peaks form and fold into batter.

Pour batter into 2 greased and floured 9 inch cake pans. Bake at 350 degrees for 30-35 minutes or until they test done. Cool in pan 10 minutes. Turn out of pans and cool completely on wire racks. Spread caramel frosting between layers, on top and sides of cake.

CARAMEL CAKE FROSTING:

3 c. sugar, divided
1 tbsp. flour
1 c. milk
3/4 c. butter
1 tsp. vanilla extract

Combine 2 1/2 cups sugar and flour in a large saucepan, stirring well, gradually add milk, stir and heat. Set aside on stove.

Sprinkle 1/2 cup sugar in a heavy 3 quart saucepan or Dutch oven. Cook over medium heat, stirring constantly until sugar melts (sugar will clump) and syrup is a light golden brown. Gradually pour about 1/4 of the hot mixture into caramelized sugar, stirring constantly, add remaining hot mixture (mixing will lump, but continue stirring until smooth). Return mixture to heat; cover and cook over low heat 2 minutes.

Uncover and cook, without stirring, over medium heat until candy thermometer reaches 238 degrees (soft ball stage) this will take about 15-20 minutes. Add butter, stirring to blend. Remove from heat and cool without stirring (about 1 hour) or until temperature drops to 110 degrees. Add vanilla and beat medium speed of an electric mixer about 20 minutes until cooled and of spreading consistency. Enough for 1 (2 layer) cake. This is a lot of trouble, but it is so very delicious.