Caramel Sheet Cake

2 cups all-purpose flour
2 cups granulated sugar
1/2 teaspoon cinnamon
1/2 cup butter
1/2 cup vegetable oil
1 cup water
1/2 cup buttermilk
1 teaspoon baking soda
1 teaspoon vanilla extract
Dash of salt
2 eggs

Mix flour, sugar, cinnamon and salt.

In saucepan bring butter, oil and water to a boil. Pour over dry ingredients and mix. Add buttermilk, eggs, baking soda and vanilla extract. Beat well. Pour into a greased and floured 10 x 15 inch pan (jellyroll pan). Bake at 400 degrees F for 15-17 minutes.

Frosting:
1/2 cup margarine
1 cup brown sugar
1/4 cup buttermilk
2 1/4 cups confectioners' sugar
1 teaspoon vanilla extract

Melt margarine. Add brown sugar and bring to a boil. Add buttermilk and return to a boil. Remove from heat. Add confectioners' sugar and vanilla extract and beat to desired consistency. Spread over warm cake.