In a large bowl, place in the cake mix, 3 eggs, 1 cup water, and the ½ cup oil. This is what my boxed cake mix called for. If your box calls for different amounts, I would follow the mix you have.
Whisk together until everything is combined and most of the lumps are gone.
Pour batter into the greased pan. Bake 35-38 minutes or until done.
Let cool.
Crumble the cake mix in a large bowl.
Add 1 cup of butter cream and mix with your fingers. Mix until all the cake crumbs are coated with buttercream.
Roll the cake pop mixture between two pieces of parchment paper and place in the fridge to set. Leave in there for at least one hour.
Cut out squares from the rolled out cake pop mixture. Place them on a cookie sheet lined with parchment paper. I just used one of the pieces of parchment paper I used to roll the mixture out with.
Place in the fridge until the fillings are ready.
Fillings
Place the buttercream in a piping bag fixed with a round or star tip.
Place the chocolate mousse in in another piping bog fixed with a round or star tip.
In a microwave safe bowl, place the heavy cream. Microwave for 2-3 minutes depending on your microwave. Make sure it's hot.
In a large bowl, pour in 2 cups of chocolate chips.
Pour the cream into the chocolate chips and let it sit for a minute.
Whisk the chocolate and heavy cream together until it is a thick, creamy, chocolate mixture.
In a medium microwave bowl, place the coating chocolate and shortening in. Microwave in 30 second intervals until chocolate is melted.
Assembling
Line the cake pop squares with the buttercream.
Fill the middle with mousse.
Place another cake pop square on the top of the buttercream and mousse.
Place the cake pop sandwiches on a cooling rack.
Put the cooling rack in a jelly roll pan. Pour a coating of ganache over the sandwich.
After all of the sandwiches are covered, scrape the extra ganache off the jelly roll pan. You can save it and place it in the fridge for another time.
Pour a coating of coating chocolate over top of the ganache. Once all of the sandwiches are overed, let them set to harden.