Instructions

Baking the cake

1. Preheat oven to required temperature as indicated on your packages of cake mix (325ºF for Bob’s Red Mill brand).
2. Use shortening to thoroughly grease two 8 inch round cake pans – you’ll want to make sure there are no bare spots. Add about a tablespoon of gluten free flour to each pan and completely coat the greased surface with the flour by rotating and tapping the pan. Feel free to add extra flour if needed – any excess flour can be dumped out or saved for the next batch of cake. Just make sure there are no large clumps of flour, especially in the edges of the pan that would create dents in the cake. Set aside.
3. Follow instructions on the package to prepare the first cake mix batter (I just did one package at a time). Divide this first batch evenly between the two cake pans. Bake according to package directions.
4. Once the first batch of cake finishes baking, move the pans to a cooling rack and set a timer for 15 minutes. While the cakes are cooling in the pans, prepare the next package of cake mix and set the batter aside.
5. Once the 15 minute timer elapses, gently jiggle the cake pans until the cake moves around freely. At this point, you can flip them out of the pan and onto the cooling rack without the cake breaking. Wash and completely dry the cake pans and prep again as you did in step 2. Repeat the same process to bake, cool, and remove the cake from the pans.

"Buttercream" Frosting

1. Cream the butter on low speed in a stand mixer. (You'll want a low speed for this entire process.) You can also do this by hand if it's too little butter for the mixer to work.
2. Incorporate the vanilla and salt.
3. Add almond milk.
4. Sift in the powdered sugar, a little at a time, until fully mixed. If the frosting seems too thick to spread, thin it out with a tiny bit of extra almond milk.
5. Move the frosting to an airtight container but before putting the lid on, press some plastic wrap against the frosting so air doesn't dry it out. Store like this when not in use.

Whipped Buttercream Filling

1. Gather the ingredients needed to make the vanilla buttercream filling. In a stand mixer with a whisk attachment, combine the powdered sugar, salt, vanilla, and almond milk on low speed until smooth.
2. Add the dairy free butter one slice at a time until incorporated. Add the shortening then whip at the highest speed for about 10 minutes or until it appears to have doubled in volume. For a cookies and cream filling, fold in crushed gluten free sandwich cookies, to taste.

Level, Fill, and Stack Cakes

1. After the cakes have cooled completely, use a bread knife, cake leveler, or your preferred method to level the cakes. Save the chocolate cake scraps for decorating the cake later. If you've used another flavor, you can quickly make a microwave mug cake using the same directions as the moss for this cake, just colored brown instead of green. You could also search online for a chocolate microwave mug cake but I haven't tried one yet so I can't make any recommendations.
2. If you’re wrapping the cake board in any sort of decorative foil, do that now (I used a pre-wrapped drum). Place the cake board centered on a cake turntable and smear a small dollop of frosting onto the middle of the cake board. Place one of your four cake layers in the middle of the cake board so it’s secured by the frosting smear.
3. If you've never stacked and filled a cake before, Wilton has a really good tutorial. If you're familiar with the process, this step should make sense. Fill a piping bag (you don't necessarily need a tip) with some of the buttercream frosting (not filling) and pipe a dam of frosting on top of your first layer. Fill inside the dam with the whipped buttercream filling you made and use the angled spatula to spread it evenly. Top with the next layer and repeat until you get to the top (the top won’t need frosting over it). When you get to the very top layer, I recommend placing it leveled side down so you get the clean edges from the cake pan on top.

Crumb Coat and Frost the Cake

1. Use a small amount of the vanilla frosting to make a very, very thin layer of frosting all over the cake. Note that this is to be a crumb coat, not the actual finished cake frosting. It's not meant to be even, perfect, or beautiful. A crumb coat is a very thin layer of frosting meant to adhere any loose crumbs to the cake which prevents them from getting into your decorative frosting that will be seen on the outside. Allow to dry, preferably in the refrigerator for about a half hour.
2. Meanwhile, set aside a couple tablespoons of the buttercream frosting for later and color the remaining with a little bit of ivory and a tiny bit of warm brown food coloring until you achieve a very light tan, warm color. Once the crumb coat has set, you can frost the top of your cake (just the top!) with it in a fairly thick layer and smooth it with an angled spatula.
3. Use a toothpick dipped in the gel food coloring to draw alternating rings of the Americolor burnt umber and chocolate brown. If it looks a little uneven or "globby" like mine, that's ok! We will smooth it out in the next step.
   
4. This step can get a little tricky so read ahead before starting. Dip your spatula in hot water to heat it up then immediately dry it off. I like a paper towel for this since it doesn't leave behind lint. Place your hot spatula across the radius of the cake, from the center of the rings to the outside, at a very slight angle, almost flat. As smoothly and uninterrupted as possible, use your other hand to turn the cake turner and smooth the top of your cake. Make one full turn and if you'd like the colors blended further, make another turn, cleaning off the spatula between full turns, if needed.
   
5. Use a clean offset spatula to scrape away any overhanging frosting from the top edge. Take your remaining light tan frosting and add chocolate brown gel coloring to darken to a chocolate color. Frost the sides of the cake and top edges of the cake board with brown frosting. It doesn't have to look nice and smooth, it just has to cover the entire side.

Add the Decorations

1. Ok, now for the fun part! Take your pre-made chocolate "bark" and place it vertically around the sides of the cake. Snap off any length you don't need. Shorter bark can be combined to cover the entire vertical height of the cake side.
2. Crumble up your leftover chocolate cake scraps and place them on the frosted cake board. Crumble up the moss cake you've made ahead and scatter it in a few places on the "dirt" and between the tree bark. 
   
3. Next, take your mushroom cookies and place them wherever you like around the base of the cake. If they don't stick well, add a little extra frosting. Be careful when handling them. I kept smearing the tops with my fingers but it wasn't too noticeable.
4. For the top of the cake, you'll want to channel your inner child. Or better yet, go get your real child and let them put the toys on top! Create a scene using model logging trucks, LEGO minifigures, and "trees". To make the fire the lego guy was using to roast his marshmallow, I just placed a birthday candle in the center of where the fire would be, broke little sticks up and placed them around the candle. Remember the couple tablespoons of frosting you reserved? Color that with a tiny bit of black (so it turns gray) to pipe "stones" around the fire. Safety first. My color separated because of the frosting recipe I used but the version I wrote for this final recipe works great.
   
   
5. Phew! That's it! You're done. Enjoy all your efforts.