Step 1: Preheat your oven to 350°F (175°C).
Step 2: In a medium bowl, whisk together the all-purpose flour, malted milk powder, cornstarch, baking soda, and sea salt.
Step 3: In a large mixing bowl, cream together the room temperature butter, dark brown sugar, and granulated sugar until light and fluffy, about 2-3 minutes.
Step 4: Add the egg and vanilla extract to the butter-sugar mixture and mix until well combined.
Step 5: Gradually add the dry ingredient mixture to the wet ingredients, mixing on low speed until just combined.
Step 6: Gently fold in the semi-sweet chocolate chips and chopped Whoppers candies until evenly distributed.
Step 7: Using a cookie scoop, drop rounded tablespoons of dough onto the prepared baking sheets, spacing them about 2 inches apart. Bake for 10-12 minutes.
Step 8: Allow the cookies to cool on the baking sheets for about 5 minutes before transferring them to a wire rack to cool completely.
