Preheat the oven to 350F. Line a large rimmed half-sheet pan with parchment paper and spray it generously with nonstick cooking spray.

Prepare the cake mix according to the instructions on the box (you can prepare them both at the same time in a very large bowl). Spread the cake batter evenly into the prepared pan and bake for 30-35 minutes, or until a cake tester comes out clean. Allow the cake to cool completely before cutting.

Dust your work surface with powdered sugar and then turn the cake out onto it. Remove the parchment and dust the top of the cake with powdered sugar as well. This will help prevent it from sticking.

Using a 4” tree cookie cutter, cut out as many trees as you can– you should be able to get about 15.

Next, use a serrated bread knife to cut the trees in half horizontally. Place the trees on a lined baking sheet and set them in the fridge to chill while you prepare the filling.

In the bowl of a stand mixer fitted with the whisk attachment, combine the heavy cream, powdered sugar, EZ Gel, vanilla pudding mix, and vanilla extract. Once combined, turn the mixer to high speed and beat until stiff peaks form– about 2 minutes.

Transfer the filling to a large piping bag fitted with a round tip.

Pipe the filling onto the bottom of one of the trees, making sure to go all the way to the edges. Place the top of the tree on the filling and press down very gently to adhere the top tree to the filling. Use an offset spatula to smooth anywhere that the filling has oozed out the sides.

Wrap the pan tightly with plastic wrap and place it in the freezer overnight, or at least 8 hours.

When the trees are frozen solid, add the white chocolate melts to a heatsafe bowl and put it over a pot of barely simmering water (making sure the bottom of the bowl is not touching the water). Stir often, just until the white chocolate has melted. Then remove the bowl from the heat.

Remove ¼ cup of melted white chocolate and set it aside in a small bowl (this will be for decorating the cakes later).

Working one at a time, dip a frozen christmas tree into the white chocolate. Allow any excess white chocolate to drip back into the bowl (an offset spatula is helpful for smoothing the top and sides of the trees) and then place the tree on a lined baking sheet. Garnish with festive sprinkles while the chocolate is still wet. Then repeat with the remaining Christmas trees.

Add 2 drops of red food coloring to the reserved white chocolate (if it cools too much, just microwave it in 15 second intervals until it is melted again). Keep adding additional drops of red food coloring until you achieve your desired color. Transfer the red chocolate to a piping bag and pipe zig-zags across the trees.

Place the trees back in the fridge and allow the chocolate to set completely before enjoying.