Using your Instant Pot’s sauté setting, whisk to combine milk, heavy cream, chocolate, sugar, and cocoa powder.
Seal the lid of the Instant Pot and set the machine to high pressure for 1 minute.
After holding high pressure for 1 minute, allow for a natural release for 5 minutes, then release remaining pressure.
Remove lid, then give a quick whisk while adding the peppermint and vanilla extracts.
Serve in a mug.
Add marshmallows, crushed peppermint, and whipped cream for garnish.
If making the spiked version - stir in the schnapps or vodka just before serving.