1. Preheat the oven to 350°F (180°C) and line a baking sheet with parchment paper or a silicone mat.

2. Cream together the butter and granulated sugar until light in color and fluffy in texture.

3. Add eggs and cake batter flavoring and mix until incorporated.

4. Add flour and baking powder and mix until a soft dough forms.

5. Add crushed cookies and mix gently.

6. Add marshmallow fluff in small dollops and gently mix to create ribbons.

7. Scoop dough and flatten slightly.

8. Bake for 12-15 minutes until cookies no longer look glossy.

9. Cool cookies completely.

10. Make buttercream by mixing butter powdered sugar and cream.

11. Divide frosting and mix marshmallow fluff into one portion.

12. Add flavoring and blue coloring to the other portion and whip.

13. Pipe frosting swirl and top with crushed cookies.