Caramel Crater Cake

1 box Duncan Hines yellow cake mix
1 small box instant vanilla pudding
1/2 cup all-purpose flour
1/4 cup vegetable oil
2/3 cup water
2 eggs
1 teaspoon vanilla extract
1 teaspoon butter flavoring

Topping:
1 cup firmly packed brown sugar
3/4 cup chopped walnuts
1 teaspoon vanilla extract
1/4 cup butter, melted

Glaze:
1 cup confectioners' sugar
Enough milk to make thin glaze
1 teaspoon vanilla extract

Heat oven to 350 degrees F. Grease and flour a 13 x 9-inch baking pan.

Cake; Measure out 1 cup of dry cake mix; set aside for topping. Combine remaining cake mix, pudding mix, flour, oil, water, eggs, vanilla extract and butter flavoring. Beat at medium speed 2 minutes. Pour into prepared pan.

Topping: Combine reserved 1 cup cake mix, brown sugar, walnuts and vanilla extract. Add melted butter and mix until crumbly (this mixture is moist). Sprinkle on top of cake batter. Carefully cut through batter with knife to create marbled effect. Bake 30 to 35 minutes.

Glaze: Mix together sugar, milk and vanilla extract and drizzle over cooled cake.

Makes 12 to 16 servings.