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

2. Beat the softened butter, brown sugar, and granulated sugar until light and creamy.

3. Add the eggs one at a time, then mix in the vanilla extract.

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

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

6. Fold in the chocolate chips.

7. Scoop large portions of dough onto the baking sheets, spacing them apart.

8. Press broken Oreo chunks and Valentine candy hearts or sprinkles onto the tops of each cookie dough mound.

9. Bake for 11 to 13 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.

11. Melt the chocolate wafers or extra chocolate chips and drizzle over the cooled cookies.