In a blender, add ice cream, Splenda Creamer, milk, ice, and food coloring. Pulse first, then blend until smooth.
Pour most of shake into a glass, leaving about a quarter of the shake in the blender. Add chocolate syrup to the blender and a splash more of milk if needed. Blend again.
Pour the chocolate layer on top of the peppermint layer. Add whipped topping if desired, along with a drizzle of chocolate syrup. Enjoy immediately!
Note
Add a drop of peppermint extract for a stronger peppermint flavor if desired.
Thin shake out with a splash more creamer if needed.