Heat oven to 375°F. Spray 15x10x1-inch pan with cooking spray.
Step
2
In large bowl, mix flour, granulated sugar, baking soda and salt. In separate bowl, beat eggs, sour cream and 1 teaspoon vanilla with whisk.
Step
3
In 1-quart saucepan, heat 1 cup butter and water to boiling. Add to flour mixture; stir until combined. Stir in egg mixture. Pour into pan.
Step
4
Bake 18 to 22 minutes or until edges are golden and center springs back when gently touched.
Step
5
Meanwhile, in 2-quart saucepan, heat 1/2 cup butter and the milk to boiling. Remove from heat; add powdered sugar in a few additions, stirring until smooth. Stir in 1 teaspoon vanilla and the chopped walnuts. Pour over warm cake. Cool completely before cutting, about 1 hour.
You can use sliced almonds or chopped pecans in place of the walnuts.
You can also bake in a 13x9-inch pan; bake 30 to 35 minutes.
