Preheat your oven to 350 degrees F and grease a mini muffin pan with non-stick cooking spray, then set aside.
In a large mixing bowl, combine the yellow cake mix, butter, and eggs with an electric mixer until it forms a soft dough.
Using a triggered cookie scoop, scoop one tablespoon of dough into each greased mini muffin cup, then bake for 9-11 minutes.
Once baked, immediately take the end of a spatula or a mini tart tamper to press into the center of each cookie to create a deep indentation, then let cool completely.
In a small bowl, combine the milk and instant vanilla pudding mix. Whisk to dissolve any lumps, then set it aside to thicken.
In another mixing bowl, beat 1 cup of the heavy cream with an electric mixer until stiff peaks form.
Add the whipped cream into the vanilla pudding mixture and beat with the mixer until well combined.
Transfer the vanilla cream into a ziploc bag or piping bag, cut off one corner, and pipe the cream into the center indentation of each cookie cup.
In a small microwave safe bowl, combine the remaining 1/2 cup of heavy whipping cream and the semi-sweet chocolate chips. Microwave for 30 seconds on high; stir well, then microwave again for 30 seconds. Stir until it becomes thick and glossy.
Spoon 1 tsp of the chocolate ganache onto the top of each cookie cup.
Let the ganache cool, then serve the cookie cups immediately or refrigerate for up to four days.