Buttermilk Spice Cake with Toasted Walnut Cream Cheese Frosting

This was Thomas' choice for his birthday cake.  I adapted this from an Emeril recipe from a few years back.  It is a delicious cake that was a perfect pairing with our Oktoberfest meal.

Buttermilk Spice Cake:
adapted from Emeril Lagasse
click here for printable version

2 cups dark brown sugar
1 stick butter, softened
1/2 cup vegetable oil
5 large eggs, separated
2 cups flour
1 teaspoon baking soda
1 teaspoon baking powder
1 teaspoon cinnamon
1/2 teaspoon nutmeg
1/4 teaspoon cloves
1/4 teaspoon allspice
pinch of salt
1 cup buttermilk

Preheat the oven to 350 degrees.  Spray 2 (9 inch) cake pans with non-stick cooking spray.
In a large bowl, with an electric mixer, cream the brown sugar and butter. With the mixer running, add the oil in a steady stream.  Add the egg yolks, one at a time, beating well after each addition.
Add the flour, baking soda, baking powder, spices and salt.  Mix well.
Add the buttermilk, mix well.

With the mixer, in another bowl, beat the egg whites until stiff peaks form.

Gently fold the egg whites into the batter.

Pour the batter evenly into the two pans.

Bake until a knife inserted is cleanly removed, about 30 minutes.
Remove from the oven and let cool on wire racks.
After the cakes have cooled, invert them onto sheets of parchment paper.

Toasted Walnut Cream Cheese Frosting:
8 ounces cream cheese, softened
6 tablespoons butter, softened
3 1/2 cups confectioner's sugar
1 teaspoon pure vanilla extract
2 tablespoons milk
1/2 cup toasted walnut pieces

In a small saucepan toast the walnuts in 2 tablespoons of the butter on medium-low heat.  Remove from heat and let cool.
In a large bowl, with an electric mixer cream the cheese and remaining 4 tablespoons of butter.
Add the sugar, 1/2 cup at a time, mixing after each addition.
Add the vanilla and milk, mix well.
Fold in the walnuts.
Frost the cake, when cool, put in refrigerator to set, at least one hour.