Preheat oven to 350°F. Line a baking sheet with parchment paper and set aside.
Cream the butter and sugar on medium speed for 1 minute. Add the eggs and vanilla extract mix until combined, being sure to scrape down the sides of the bowl with a rubber spatula.
Add the 1 cup of white cake mix, 2 ¼ cups flour, 1 tsp cornstarch, ¾ tsp baking soda, and ½ tsp salt and mix to combine.
Portion the dough into ¼ cup sized balls and then using the palm of your hand gently press down on the ball until it is a thick disk.
Bake for 9 minutes. Remove from oven immediately press the bottom of a 1/3 cup measuring cup (or any measuring cup that is smaller than the cookie) into the center of each cookie. (I like to spray the bottom of the measuring cup I’m using with nonstick cooking spray. This isn’t’ necessary but I do like that it prevents the cookie from sticking to the measuring cup. If you have any questions about this part of the recipe, refer to the blog post as I have photos illustrating exactly what the cookies should look like). Bake an additional 2-3 minutes. Remove from the oven and let cool on pan for 10 minutes then transfer to a wire rack to cool completely.
Cheaters Vanilla Pastry Cream
In a medium bowl whisk the instant pudding, milk, and vanilla extract for 2 minutes. Mix until the mixture is very thick. Using a rubber spatula fold in the cool whip. Cover and store in the fridge until ready to use. This mixture is thick and will not be runny at all.
Chocolate Ganache
Place the chocolate in a heat proof bowl. Add the heavy cream to a small pot over medium heat. Bring mixture to a boil. Once boiling pour the heavy cream over the chocolate and let sit for 3 minutes. Add the pinch of salt.
Use a whisk and starting in the center, slowly whisk in a circle until smooth.
Assembly
Place 3 tablespoons of pastry cream in each cookie well. Smooth into an even layer.
Add a dollop (about 1-2 tablespoons) of chocolate ganache to the top and spread in a small circle, not covering the entire surface of the cream though.
Serve chilled.
Notes
Store cookies covered in an airtight container in the fridge for 2-3 days. Cookies that aren’t topped with vanilla cream and ganache can be stored in an airtight container or Ziplock bag at room temperature for 2-3 days or in the fridge for 5-6 days. The cream and the ganache should be refrigerated.