3⁄4 cup peanut butter and milk chocolate chips (or use 3⁄8 cup each peanut butter chips and milk chocolate chips if you can’t find the combination bag)
Preheat the oven to 350°F. Line two baking sheets with parchment paper.
In a large bowl, stir together the cookie mix, egg, melted butter, and cornstarch until a soft dough forms.
Fold in the peanut butter and milk chocolate chips, toffee bits, and Halloween jimmies until evenly combined.
Using a 1-tablespoon cookie scoop, scoop the dough onto the prepared baking sheets, spacing the cookies about 2 inches apart. Gently press an edible witch hat into the top of each cookie.
Bake for 8 to 9 minutes, or until the edges are set and the centers still look slightly soft.
Immediately sprinkle the warm cookies with a pinch of flaky sea salt.
Let the cookies cool on the baking sheet for 5 minutes before transferring them to a wire rack to cool completely.