1. Preheat the oven to 350°F and line two baking sheets with parchment paper.

2. In a medium bowl, whisk together the flour, cocoa powder, cornstarch, baking soda, and salt.

3. In a large bowl, beat the softened butter, brown sugar, and granulated sugar until light and fluffy.

4. Add the eggs one at a time, mixing well after each addition, then mix in the vanilla extract.

5. Gradually add the dry ingredients to the wet ingredients and mix just until combined.

6. Fold in the crushed Oreo cookies, chocolate chips, and candy-coated chocolates.

7. Scoop large portions of dough, about 3 tablespoons each, onto the prepared baking sheets, leaving space between each cookie.

8. Press a few extra Oreo chunks and candy pieces onto the tops for a bakery-style look.

9. Bake for 11 to 14 minutes, until the edges are set and the centers still look slightly soft.

10. Let the cookies cool on the baking sheet for 10 minutes, then transfer to a wire rack to cool completely.

11. Melt the semi-sweet chocolate with the coconut oil or heavy cream until smooth.

12. Drizzle the melted chocolate over the cooled cookies, then top with extra crushed Oreos and Valentine sprinkles.

13. Let the chocolate set before serving or storing.