Preheat oven to 350 degrees and grease a (approximately 10” x 15”) rimmed baking sheet pan (AKA a jelly roll pan) with butter and flour (tap off extra flour).

In a large mixing bowl add softened butter, avocado oil, and sugar. Mix with an electric mixer with beater attachments on low speed for 2 minutes. It should be creamy and well-combined.

Add eggs one at a time, beating until completely combined both times.

Add in vanilla, sourdough starter (fed or discard, doesn’t matter), milk, sour cream, salt, and baking powder. Mix on low-speed just until combined. Do not over mix.

Add in flour and mix on low speed just until combined. Do not over mix.

Optional- at this point you can move on our the recipe or you can long ferment the batter for gut benefits. This allows the sourdough cultures to ferment the other ingredients making them easier to digest. To do this long ferment cover the bowl of batter with a lid or seran wrap and place it in the fridge overnight or up to 24 hours. (Minimum 12 hours)

Pour cake batter onto the prepared baking sheet. Spread evenly with a spatula to fill the entire pan.

Bake for 20-24 minutes or until a toothpick comes out clean.

During this cooling time, in a medium sized mixing bowl, add in cold heavy whipping cream, vanilla extract, softened cream cheese, and powdered sugar.

Use an electric mixer on medium speed with a whisk attachment to whip the ingredients together for 2-3 minutes or until stiff peaks form. The whipped cream should stay on the whisk and not drop off.

If the heavy whipping cream isn’t cold the whipped cream won’t come together. If this happens place the bowl in the freezer for 5-10 minutes and try again.

You can also do this with a regular handheld whisk it’ll just take a little longer.

Store in the fridge until you’re ready to use it.

In a pan over low heat melt the chocolate chips of your choice. Stir continuously to prevent burning. Warm until smooth, about 6-8 minutes. Don’t turn up the heat to go faster it will burn the chocolate.

When melted take off the heat and set aside for now.

When the cake is fully cooled, take a spatula and loosen the edges as well as underneath the cake. Be very gentil not to crack the cake.

The cake should be about 3/4” thick (If your pan was larger than my 10”x15” pan your cake will be a little thinner or if it was smaller the cake will be thicker.)

Then place a cutting board on top of the pan and flip it upside down so the cake is now out of the pan and upside down on the cutting board. The cake should come out easily if you loosened it all the way.

Leave the cake upside down and take a 4” Christmas tree cookie cutter and cut out 8-10 trees. Try to cut the trees as close to the edges as possible so you can try to squeeze two out of the center.

Set the excess cake aside (you can use this for another recipe like cake pops, or you can cut it up and save it or freeze it for later).

Spread 2-3 spoonfuls of filling on half of the trees. We’re going to make little cake sandwiches so make sure you’ve got a good ratio of whipped cream to cake.

Then place a plain tree on top of each whipped cream covered tree.

Now to coat the trees grab the chocolate you melted earlier. If it’s hardened warm it slowly again.

For coating them you have a few different options you can choose from. PLEASE SEE THE NOTES TO CHOOSE WHICH ONE AND DO IT.

Once you’ve coated your trees immediately sprinkle the tops with decorating sugar.

After that enjoy! Because of the whipped cream these cakes need to be stored in the fridge in an airtight container.