First, make the cake. Preheat oven to 350F and spray two 6" round cake pans with nonstick baking spray.

In a small bowl, whisk together the ground flaxseed with the water and set aside to thicken.

In the bowl of a stand mixer, combine the flour, baking powder, baking soda, salt, and sugar.

Add in the vegan butter, and beat on low until it's incorporated and has a sandy texture.

In a small bowl, whisk together the oil, flaxseed mixture, nondairy yogurt, and vanilla extract, and add them to the dry ingredients. Mix until combined.

Pour in the milk, and beat on medium-low until smooth and creamy. Finally, toss in the Halloween sandwich cookies, roughly crushed with your hands, and beat a few times to combine.

Divide batter evenly among the 2 pans, and bake for 35-40 minutes until cake is set in the center and a toothpick comes out clean.

When the cakes are completely cooled, you can make the black frosting. In the bowl of a stand mixer, beat the shortening, vegan butter, and vanilla extract together until completely smooth and creamy. Add in the cocoa powder, followed by the powdered sugar, 1 cup at a time, until a thick frosting forms. Add in the salt. It is normal to need to add 1-2 tablespoon of milk to get the right consistency. Add in the black food coloring.

To assemble the cake, divide the 2 cake layers in half to create 4 thin layers.

Place one cake piece on your cake stand or platter, and spread some black frosting on top. Repeat with all.

Be sure to set some black frosting aside to decorate the top.

Place the cake in the fridge while you make the orange frosting.

In the bowl of a stand mixer, beat the shortening, vegan butter, and vanilla extract together until completely smooth and creamy. Add in the crushed sandwich cookies, followed by the powdered sugar, 1 cup at a time, until a thick frosting forms. Add in the salt. It is normal to need to add 1-2 tablespoon of milk to get the right consistency. Add in the orange food coloring.

Crumb-coat the cake with a thin layer of orange frosting, and place in the fridge to set for a about 10 minutes.

In the meanwhile, prepare your cookies for the "fault" line effect. Carefully split your cookies and remove the cream filling, saving the Halloween design side for decorating. Be sure to save some cookies for decorating the top as well.

Time to make your fault line effect. Grab your prepared Halloween cookies, and stick them to the center of the cake using a bit of frosting. You can also add some crushed cookie pieces between the gaps if you want (not a big deal as the frosting will cover most of this area).

Spoon you orange frosting onto the top of the cake, and around the sides, avoiding the sandwich cookies. Be sure to make this THICK. The frosting MUST stick out further from the cake than the cookies to avoid making a mess.

Using a bench scraper, carefully smooth the sides, trying to avoid smearing too much frosting onto the sandwich cookies.

When your cake looks like you want it, go ahead and add the black crystal sprinkles around the fault line edges. You must do this now while the frosting is still soft so they will "stick"!

Place your cake in the fridge after you finish the black crystal sprinkles.

To decorate the top, grab your reserved black frosting, and place in a piping bag fitted with the 1M tip.

Pipe tall swirls of frosting around the edge of the cake, and place a sandwich cookie between each swirl. Sprinkle Wilton Halloween sprinkles on top.

Keep cake in the fridge until ready to serve. Enjoy!!