Melt the semi-sweet and milk chocolate chips in the microwave (or on the stovetop) for 1 ½ to 2 minutes, stirring often to make sure it's not burning. Stir till all the pieces have melted fully.
Stir the peppermint extract into the chocolate.
Pour the melted chocolate into the silicone ice cube tray. Spread evenly between at least 10 molds.
Add a bamboo or other lightweight spoon to each of the molds with chocolate.
Top the chocolate with a tablespoon of mini marshmallows for each mold.
Refrigerate the chocolate spoons for at least 1 hour to let the chocolate harden.
To Serve - Pop the hot chocolate spoons out of the silicone ice cube molds. Heat a cup and a half of milk on the stovetop or in a microwave, add to a mug, and stir the hot chocolate spoon in the hot milk till it's fully combined.