Preheat oven to 350ºF and line quarter sheet 9x13 baking pan with parchment paper (see notes).

Sift coconut flour into medium bowl. If you can't sift, make sure no lumps are present. Whisk in cocoa powder, tapioca flour, instant coffee, baking soda, baking powder and salt. Set aside.

Using electric hand mixer or stand mixer with fitted paddle attachment, combine maple syrup and applesauce  on medium speed until smooth. Add nut/seed butter mixing on medium-high speed until combined. Add vanilla extract then eggs two at a time, mixing on low-medium speed until combined.

Pour dry ingredients into bowl of wet ingredients and combine on low-medium speed. With mixer running on low speed, carefully add milk and mix until batter is smooth – if lumps are present try breaking with fork. Immediately pour batter into prepared sheet pan, spreading smooth with spatula.

Bake cake for 22-28 minutes, until inserted toothpick in center comes out clean. Watch baking time at 20 minutes as oven temperature can vary. Allow cake to cool completely before frosting – about 1 hour at room temperature, or place in fridge for about 30-40 minutes.

Meanwhile, prepare frosting: In a large bowl using electric mixer, beat shortening until creamy then slowly add in cocoa powder and powdered sugar, mixing on low speed and gradually moving to high speed. Add in vanilla, then milk about two tablespoons at a time and continue mixing on medium speed, finishing with high speed at the end for about 20 seconds, until smooth and creamy. 

Frost cake evenly and sprinkle with chocolate shavings or sprinkles, if desired. Cut and serve! 

Cake can sit at room temperature depending on frosting used, but probably best stored cold.