Triple-Play Chocolate Cake

My mom, the amazing grandma and mom that she is, got me a cookbook for my birthday called Learning to Bake Allergen-Free A Crash Course For Busy Parents on Baking without Wheat, Gluten, Dairy, Eggs, Soy or Nuts.  She, also, got me some xanthan gum.
Thankfully, my birthday is 5 days before my youngest's.  So, I got to try out a cake recipe today for his 4th birthday and it was a success!  So, much so that there are only 10 pieces of a 9x13 cake left.

2 1/2 cups gluten-free flour blend (I used Bob's Red Mill flour blend)
1/2 tsp xanthan gum (leave out if your flour blend contains xanthan gum)
1 1/2 cups sugar
1/2 cup unsweetened cocoa powder
4 tsp baking powder
1 tsp salt
4 Tbsp shortening
1 cup allergen-free chocolate chips
1/2 cup unsweetened applesauce (I used homemade)
1 cup flaxseed gel (equal to 4 eggs) (I used 4 eggs)
2 cups chocolate milk (I used raw cow's milk)
2 tsp vanilla extract

1 Preheat the oven to 350 degrees.  Spray 9x13 pan with cooking oil.
2 Mix the flour, xanthan gum (if needed), sugar, cocoa powder, baking powder, and salt together in a medium bowl.  Set it aside.
3 Melt the shortening and the chocolate chips together in a small bowl.  Stir these two ingredients together thoroughly.
4 Combine the applesauce, flaxseed gel, milk, and vanilla together in a large bowl, with a mixer on medium-low speed, about 1 minute.
5 Add the chocolate and shortening mixture and blend for 1 more minute.
6 Gradually, add the flour mixture to the wet ingredients.  Blend completely.
7 Pour the batter into the prepared cake pan.
8 Bake at 350 degrees for 35-40 minutes, until a toothpick comes out clean.