What on earth do you do when you unexpectedly find yourself with a spare box of Betty Crocker Spice Cake

Mix?

If anyone even thought "mix and bake as-is", you're officially banned from this website. Because a quick peek into The Cake Mix Doctor Returns! reveals a far more appetizing concept: Applesauce Bars with Cream Cheese Frosting. Apparently, this is remnicient of a regional southern store-bought cake that enjoyed popularity at A&P stores called "Spanish Bar Cake", a dense spice cake studded with raisins and nuts and topped with delicious cream cheese frosting. Well, my version is doctored a bit more--with finely chopped apples instead of applesauce, no raisins (ew) and even fattier frosting than the one in the book, and I assure you, they're a delightful autumn treat. I don't have a picture but they are similar in appearance to this gorgeous specimen by PastryMama, pictured above (she's got a great recipe too!).

Perfect for breakfast.

Apple Walnut Bars with Cream Cheese Frosting

For the bars

parchment paper, to line pans

1 package plain spice cake mix
1/4 cup brown sugar, lightly packed
3/4 teaspoon cinnamon
1/2 teaspoon ground nutmeg
1/4 teaspoon ground cloves
2 apples, very finely chopped (I used Granny Smith, with the skin on)
3/4 cup butter, softened
4 large eggs
1/2 cup finely chopped walnuts

For the frosting

4 ounces cream cheese (I used full-fat, original recipe calls for light...whatever)
1 tablespoon milk
2 1/2 cups confectioners' sugar, sifted
1 teaspoon vanilla
1/2 cup coarsely chopped walnuts, for garnish/topping (optional)

Procedure

Make the bars. Place a rack in the center of the oven and preheat oven to 350 F. Line a 15x10 inch jelly roll pan with parchment paper. Put the pan aside.
Place the cake mix, brown sugar, spices, chopped apples, butter, and eggs in a large mixing bowl and beat with an electric mixer on low speed until the ingredients are incorporated, 30 seconds. Stop the machine and scrape down the side of the bowl with a rubber spatula. Increase the mixer speed to medium and beat until the batter is smooth, about 1 minute longer. Fold in the finely chopped walnuts. Transfer the batter to prepared pan, smoothing the top with a rubber spatula.
Place the pan in the oven and bake the bars until the edges have set and the center is still a little soft (press it lightly with a finger), 25-30 minutes. Transfer the pan to a wire rack and let cool for about 35 minutes.
Make the frosting. Place the cream cheese in a large mixing bowl and beat with an electric mixer on low until creamy, 1 minute. Stop the machine and add the milk, confectioners' sugar, and vanilla. Continue beating on low until the ingredients come together. Increase the mixer speed to medium low and beat until the frosting is creamy and light, 30 seconds longer. Spread the frosting evenly on top of the cooled cake. Run the tines of a fork through the frosting to make squiggles, or garnish with coarsely chopped walnuts. Let the frosting set for 10 minutes before slicing and serving.
Storage suggestion: store the bars, covered withfoil, in the fridge for up to one week--or, freeze the bars in the pan, covered with foil, for up to three months. Let bars thaw overnight before serving.