Buttermilk Spice Cake with Toasted Walnut Cream Cheese Frosting

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.