Line a large baking tray with grease proof paper or a silicone mat.
Place the dark and milk chocolate into a medium sized heat proof bowl and place in the microwave in 20 second increments, stirring in between each one until all the chocolate is melted.
Alternatively, place the heat proof bowl over a saucepan of simmering water and stir gently until melted.
Pour the melted chocolate into the centre of your prepared pan and then use a small angles spatula to spread the chocolate into a thin layer; around 2mm thick. I covered my baking tray apart from a 1/2 inch gap around the edge.
Use your writing icing to draw eyes, a nose and a mouth on 8 of the white chocolate buttons. I'm not very artistic, so I did two black dots for eyes, a red blob for a nose (I didn't have orange icing) and then a few black dots in a smile shape for a mouth.
Place one of your faces into the melted chocolate and place 2 plain buttons underneath to make a 3 button snowman shape. Place a Rolo above his face and place one half of a Pretzel stick either side of the gap between the first and second white chocolate button. That's the basic shape: repeat this until you have 8 snowmen arranged randomly in your melted chocolate.
Leave to set for 30 minutes before putting in the fridge for 15 minutes to set fully.
Break into pieces - I actually used a sharp, hot knife to cut around each snowman so each piece of bark had one snowman in; you can try and carefully break it around the snowmen, or you can use a knife.
Snowman Bark can be kept in an airtight container, at room temperature, but in a cool, dark place, for 5 days.
You can also place pieces of bark into clear bags and tie them with a cute Christmas ribbon to gift to friends and family!