In a medium saucepan over medium-low heat, add milk and candy corn.
Let heat while stirring occasionally, until candy corn has completely dissolved into milk and milk is hot, but not simmering. This should take about 10 minutes.
Pour candy corn hot chocolate into mugs, top with mini marshmallows, and enjoy.
Optional: If you want to rim mugs with sprinkles before serving, place sprinkles on a plate, brush rims of mugs with simple syrup or water, and roll mug upside down on plate to coat rim in sprinkles.