Add three cups of water to Instant Pot cooking pot, lock on Lid and close Pressure Valve. Push the Sterilize button, then Pressure button to change to High and then the "-" button and adjust down to 5 minutes. When Beep is heard, do a Quick Release. When all pressure has been released, remove lid and dump out the water. Dry and cool off cooking pot.
Make Yogurt (Not Under Pressure)
Pour Milk/Cream into cool Pressure Cooker cooking pot. Cover with IP Lid or Glass Lid. Push Yogurt button twice (or until is says boil).
When Beep sounds, remove Lid and take temperature, which should read 180 degrees. Remove cooking pot to sink full of cold water and cool down to 95-110 degrees. Place pot back into Instant Pot.
Add Starter and whisk together. Add smashed Mexican Chocolate (reserving 1/2 bar for after incubation) and replace Lid. Press Yogurt button until it says 8:00/Normal. Adjust down to 6:00/Normal. Time should count UP, not down.
When time is up, whisk yogurt and sugar, if desired. Taste and add more Mexican Chocolate, leaving some in Crumbles, if desired. Pour yogurt into Popsicle Mold(s) and place in freezer.