Preheat oven to 350 degrees.
Grease a 9x9" square pan.
Prepare the cake mix according to the package directions.
Add the nutmeg to the batter and mix well.
Bake the cake according to the package directions.
Allow to cool completely.
In a saucepan, heat the cream, coconut milk and egg yolks.
Stir until it starts to bubble around the edge of the pan, but do not boil.
Remove from the heat.
Whisk the powdered sweetener and xanthum gum in a small bowl.
Alternatively, you can prepare a box of the Simply Delish vanilla pudding.
Add 2 Tbsp. butter and stir until melted.
Poke holes in the cake with the end of a wooden spoon.
Pour the cream mixture over the cake.
Cover and refrigerate at least 2 hours.
In a saucepan, heat the remaining cream and butter.
Remove from the heat and add the chocolate and vanilla extract.
Stir until the chocolate melts.
Pour the ganache over the chilled cake.
Refrigerate until the ganache has set up.