There's nothing like picking up a bite-sized Boston Cream Pie Cookie cup and just popping it in your mouth. They're soft, delicious, and give you that sweet taste and flavor that you're craving.
Preheat oven to 350F.
Spray a mini muffin pan with non-stick cooking spray; 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. Scoop the cookie dough by rounded teaspoons into the greased mini muffin cups (you will need to make a total of 36 evenly sized cookie cups). Do not overfill the muffin cups; they should each be no more than 2/3 full of cookie dough.
Bake the cookie cups at 350F for 9-10 minutes until set. Remove from the oven and cool in the pan for 5 minutes
Use the end of a wooden spoon or a mini tart shaper to press into the center of each cookie to create a deep indentation where the cream filling will later be added. Run a butter knife around the edges of each cookie to release it from the pan. Cool completely to room temperature on a wire cooling rack.
In a small bowl, combine the milk and instant vanilla pudding mix. Set aside.
In a large mixing bowl, beat 1 cup of the heavy cream with an electric mixer until stiff peaks form. Spoon the vanilla pudding mixture into the whipped cream and beat with the mixer until well combined. Scoop the vanilla cream into a gallon size zip top bag; zip closed and cut one corner off of the bag to create a piping bag. Pipe the cream into the center indentation of each cookie cup.
In a small microwave safe bowl, combine the remaining ¼ cup of heavy whipping cream and the semi-sweet chocolate chips. Microwave for 15 seconds on high; stir well, then microwave again for 15 seconds. Stir the chocolate mixture well until it becomes thick and glossy. Spoon a small amount of the chocolate onto the top of each cookie cup.
Serve the cookie cups immediately or refrigerate for up to three days.