• Preheat the oven to 350℉. Prepare a 9x13-inch cake pan and spray with cooking spray. Set aside. 

Make The Apple Spice Cake

• In a large bowl, add the spice cake mix, water, oil, and eggs. Use an electric hand mixer, or use the bowl of a stand mixer with the paddle attachment, to beat at medium speed for 2 minutes or until well blended and combined. 
  1 box (13.25 oz) spice cake mix, 1 cup water, 1/2 cup vegetable oil, 3 large eggs
• Stir in the chopped Granny Smith apples, apple pie spice, vanilla extract, and chopped pecans (optional). 
  2 Granny Smith apples, 2 teaspoons apple pie spice, 1 teaspoon vanilla extract, 1/2 cup finely chopped pecans
• Pour the apple cake batter into the prepared pan. Spread it out evenly using a spatula. Bake for 20-25 minutes or until a toothpick inserted into the center of the cake comes out clean. 
• Remove the cake from the oven and allow the cake to cool, inside the pan at room temperature, for about 10 minutes. Transfer the cake pan to a cooling rack to cool completely. 

Make The Cream Cheese Frosting

• In a large mixing bowl, using an electric hand mixer, beat the cream and butter until smooth and creamy.
  1 bar (8 oz) cream cheese, 1/2 cup (1 stick) butter, 4 cups powdered sugar
• Add the powdered sugar, 1 cup at a time, beating on low speed until fully incorporated.  
• Add 1 tablespoon milk and the vanilla extract and continue beating until the frosting is light and fluffy. If frosting is too thick, add more milk, one tablespoon at a time, until you reach your desired consistency.

  ^{* The higher fat percentage of milk you use, the more you will need of it. The lower fat percentage of milk, you will need less of it in order to achieve a thick but spreadable consistency.}
  1 teaspoon vanilla extract, 1-2 tablespoons milk
• Once the cake has cooled completely, spread the cream cheese frosting evenly over the top of the cake. If wanted, add some chopped pecans and a sprinkle of ground cinnamon over top the frosting. 
  1/4 cup finely chopped pecans, dash of ground cinnamon