Preheat the oven to 350°F (175°C) and line a baking sheet with parchment paper.

1. Cream the butter, brown sugar, and granulated sugar on medium speed for 3-4 minutes until light and fluffy.
2. Add eggs one at a time, beating well after each addition. Mix in vanilla extract.
3. In a separate bowl, whisk together flour, black cocoa powder, 2½ cups Oreo crumbs, baking soda, baking powder, and salt. Gradually add to the wet ingredients, mixing until just combined.
4. Scoop out approximately 3 tablespoons of dough, roll into balls, and roll in the remaining Oreo crumbs. Place the dough balls on the prepared baking sheet.
5. Refrigerate dough for 2 hours. Then, bake for 12 minutes or until edges are set. Cool on the baking sheet for 10 minutes before transferring to a wire rack.
6. Prepare the frosting by whisking together instant chocolate pudding mix, heavy cream, milk, powdered sugar, cocoa powder, and vanilla extract until smooth and thickened. Refrigerate until ready to use.
7. Once cookies have cooled, spread chocolate pudding frosting over each cookie, sprinkle with Oreo crumbs, and top with a gummy worm.