Line a baking sheet with parchment paper; set pan aside.
Preheat oven to 350°F.
Using a stand mixer, cream together butter and sugar until light and fluffy (~3-4 minutes on medium speed).
Add cocoa powder, salt and baking powder; mix until well combined.
Add eggs, whipping cream, food coloring, vanilla extract and vinegar; mix until well combined.
Add flour; mix until well combined.
Transfer dough to prepared baking sheet. Shape dough into a 5”x10” rectangle. (Tip: The red food coloring will leave your hands red. To prevent this, wear disposable gloves.)
Bake for 25 minutes.
Remove pan from oven and let cool for 10 minutes.
Reduce oven temperature to 325°F.
Transfer biscotti to a cutting board and slice crosswise into 5”x¾” pieces. Place each piece cut-side down on parchment-lined baking sheet.
Continue baking for 25-30 more minutes, or until biscotti are slightly crispy to the touch.
Let biscotti cool for 5 minutes on pan before transferring to wire racks until completely cool.
For the Cream Cheese Glaze
Using a small bowl, whisk together all of the ingredients until smooth.
Using a piping bag with a small round tip (or a ziptop bag with one tiny corner snipped off), drizzle the glaze over the cooled biscotti.