First, start by melting the chocolate chips in the microwave-safe bowl in 30 seconds increment, stir between each one.. Keep microwaving in 30-second increments until the chocolate if fully melted.
If using the gold dust, take a pastry brush, dip it in the golden dusts and brush each cavity with the powder.
Add a tablespoon of the melted chocolate into each mold cavity. Using the back of a spoon, smooth out the chocolate on the sides of each mold. If there isn't enough chocolate to coat the inside of the molds add a little bit at a time and smooth it over again. Place the mold in the freezer for 15 minutes or until the chocolate is completely solid.
Pull out the hardened chocolate by pulling and gently stretching the silicone mold. The chocolate will pull away from the mold and you can either remove it from there using your hands (I like to wear gloves for this step to avoid finger prints on the chocolate) or flip your mold onto a parchment lined baking sheet and push the top gently while lifting the mold. If you are working in a hot kitchen and notice your chocolate domes starting to melt, put them back in the freezer right away to harden again.
Now, you can slightly heat up a pan or a plate, place them on your work surface and proceed to fill up a dome of chocolate with 1 tbsp of hot chocolate mix and about 6 marshmallows. Now, press one of the empty chocolate domes against the warm plate or pan to slightly melt the rim. Place your empty chocolate dome over the filled one and gently press to seal. Work fast, as we don't want our chocolate spheres to melt.
Store them in an airtight container in the fridge.