Step 1: Preheat your oven to 350°F (175°C) for even baking.
Step 2: Line a baking sheet with parchment paper to prevent sticking.
Step 3: In a large mixing bowl, whisk together the powdered sugar, salt, cocoa powder, and cornstarch until well combined.
Step 4: In another bowl, whisk the egg whites until frothy.
Step 5: Add the whipped egg whites and vanilla extract to the dry ingredients, stirring gently to form a thick batter.
Step 6: Fold in the chocolate chunks and half of the Valentine M&Ms into the batter.
Step 7: Using a cookie scoop or tablespoon, drop rounded balls of dough onto the prepared baking sheet.
Step 8: Press a few of the remaining Valentine M&Ms onto the tops of each cookie.
Step 9: Bake for 10-12 minutes until the edges look set and the centers are still soft.
Step 10: Let the cookies cool on the baking sheet for a few minutes before transferring them to a wire rack.
