Whisk Nesquick powder and corn starch in a sauce pan, gradually add the milk and place the sauce pan on medium heat.
Cook and stir occasionally until thickens, about 8-10 minutes. Turn the heat off, cover the pudding with a plastic wrap and set aside to cool.
Preheat the oven to 350 F. For each cup in the muffin tin use 1 1/2 tablespoon cookie dough and gently use your fingers to flatten the dough in the cup and make a well. Repeat with the remaining dough.
Bake in the oven for 12 minutes until the edges are light brown.
The cookies will inflate. Take the muffin tin our of the oven, using a shot glass, very gently press down the cookie to deflate it and form a well again. Be very gentle and don't press hard.
Bake in the oven for an additional 2 - 3 minutes.
Take the muffin tin out of the oven and let it cool for 5 minutes, then take out the cookie cups carefully and let them cool completely on a rack.
To serve, fill the cups with chocolate pudding and top with crushed Butterfinger.