Preheat the oven to 375 degrees and line a baking sheet with parchment paper. Whisk together the flour, cornstarch, baking soda, and salt. Set aside.

In a large bowl, beat together the butter, brown sugar, and sugar until creamy.

Add the eggs and vanilla and beat to combine. Add the dry ingredients and beat until a thick dough forms. Fold in the Reese’s Pieces and chocolate chips.

Use an ice cream scoop to scoop the dough onto the prepared baking sheet. Use the back of the scoop to press the top of the cookie down slightly. Top with additional Reese’s Pieces, if desired.

Bake in the preheated oven for 13 to 15 minutes, until the edges of the cookies, are brown but the center is still soft. Allow the cookies to cool on the pan until the center sets, then transfer the cookies to a wire cooling rack to cool completely. Serve with a nice cold glass of milk and Enjoy!