Boston Cream Poke Cake

INGREDIENTS:
FOR THE CAKE
1 box butter recipe yellow cake mix plus ingredients called for on package (vegetable oil, eggs, water)
6.8 oz instant vanilla pudding
4 cups whole milk
1 tsp vanilla extract
FOR THE GANACHE
2 tbsp butter
1 cup semi-sweet chocolate chips
1 cup milk chocolate chips
2/3 cup heavy cream
1 tsp vanilla extract
INSTRUCTIONS:
Make the yellow butter cake mix per package directions. Pour into a lightly greased 9×13 baking dish. Place in the oven and bake at the recommended temperature and time per the cake box directions.
Remove cake from the oven and let cool. Once cooled use the back of a wooden spoon to poke holes all over the top of the cake, about an inch and a half apart. Set aside.
In a medium mixing bowl combine instant vanilla pudding, whole milk, and vanilla extract. Use a whisk to combine.
Immediately pour the pudding mixture over the top of the cake before it has a chance to set up.
Place the cake in the refrigerator for 1 hour.
In a medium mixing bowl combine butter, semi-sweet chocolate chips, milk chocolate chips, heavy cream, and vanilla extract. Stir together. Place in the microwave for 30 seconds. Remove and stir together. Repeat steps in 30-second increments until the chocolate is melted and the mixture is combined.
Pour the chocolate over the top of the cake and place it in the refrigerator for at least 4 hours or overnight if you have the time.