Prepare the batter for your gluten free cake mix according to directions. If using a 15 - 16 oz cake mix, bake in TWO 10 x 15 jelly roll pans. (Or bake one batch and then reuse. If using a 18-22 oz cake mix, I recommend using 2 11x17 pans.

ONLY BAKE FOR 10 minutes. Longer than this, and you'll have burnt cake on your hands. Remove baked cake from pans and allow to cool completely.

Meanwhile, prepare your marshmallow cream filling. Make sure your butter is room temperature and soft, before starting. Mix using a hand mizxer, or a Kitchenaid stand mixer. (I like the stand mixer, because I can walk away.)

Stretch the mouth of a piping bag over a tall glass, then fill the piping bag with filling mixture. Set aside.

Once cake is cooled, cut cake into tree shapes, using a cookie cutter. Pipe filling on to the bottom piece of cake. Don't be afraid to be generous with the filling. You have plenty of filling! Place another tree cake cutout on top of filling

Once all tree cake bottoms have been topped with filling and a top cake, place in freezer for 20 minutes, before coating.

Meanwhile, melt candy coating / almond bark in a glass bowl, set over a hot pot of water. To that, add your shortening, if needed. I used 16 oz of vanilla candy coaring, and added a tsp of shortening. You can make your coating thinner if you like, but I would test that out with a small portion of melted bark, and not a whole bowl of melted white chocolate. 

Place christmas tree cake on fork, and dunk completely in bowl of melted candy coating. Use spoon to fully coat, if needed. Tap / bounce cake over bowl, to get rid of excess coating.

Place finished cake on parchment and allow to coating to set. **Note- If you want to add sprinkles or colored sugar, you need to do this BEFORE the coating sets.

**Note - If you have leftover filling, this can last in the fridge for 5 days. I used my leftover filling to the cake scraps to make cake balls. I don't have an exact measurement of frosting to tell you to add. Use just enough for the cake to hold together. Dip chilled cake balls in remaining melted candy coating.