AntiGravity Gear makes this one:
It's basically a Ziploc plastic bowl insulated with, I believe, Reflectix. The insulation is glued to the cover but the bowl part can be removed from the insulation.
You could DIY with a 2-cup bowl.
When solo, I use my cooking pot. With the grandkids, each has his/her own color of the GSI Cascadian cups.