300gramssolid dark chocolate bars, chopped(about 11oz)
300gramssolid white chocolate bars, chopped(about 11oz)
Line a rimmed baking sheet with tin foil and set aside.
Make a double boiler to melt your chocolate: place 1" of water in a small pot and bring it to a simmer over medium high heat.
Find a glass bowl that fits over the top of the pot and sits on the top edges, but will not touch the water. Add the dark chocolate and 1/2 teaspoon mint extract to the bowl and place it over the simmering water. Stir frequently until melted and smooth.
Spread chocolate on foil in baking sheet with an offset spatula -- it will cover most of the pan, but maybe not all of it, depending on how thick you want your bark to be. Set in the fridge to set.
Place your white chocolate and remaining 1/2 teaspoon mint extract in a clean glass bowl that also fits over your double boiler, and repeat the process to melt the white chocolate.
Stir in half of the crushed candy canes.
Remove baking sheet from the fridge and spread the white chocolate over top. Sprinkle with remaining candy canes, pressing gently into the chocolate before it sets.
Allow to set at room temperature or in the refrigerator for 1 hour, before breaking into chunks and serving.