Line a cookie sheet or similar pan with parchment paper or non-stick foil.
If you plan to top with candy cane bits, put unwrapped candy canes in a baggie and use a rolling pin, veggie can, mallet, etc. to break them up into small bits. You’ll need to have these ready ahead of time. Kids love to help with this part, so put them to work!
Melt the chocolate chips/chunks in a double-boiler* (best) or in the microwave, stirring frequently. Once melted, add 1/4 tsp peppermint extract and stir. Pour into the pan and spread to desired thickness (I aim for 1/4 inch thick). Put the pan in the refrigerator to chill for at least 5 minutes.
In a clean pan/bowl, melt the white chocolate in a double-boiler (best) or in the microwave, stirring frequently. Once melted, add 1/4 tsp peppermint extract and stir. Remove the pan from the refrigerator and pour the melted white chocolate on top and spread to cover the dark chocolate. Sprinkle on peppermint bits and/or mini chips.
Chill for 2 hours to set (though it may be ready sooner than that). Break into pieces. Store in the refrigerator, as it has a fairly low melting temp. It never lasts very long at our house, so blooming isn’t an issue.
It’s difficult to find milk and soy-free white chocolate, so if you need to be milk and soy-free, you can make this with only safe dark chocolate and the crushed candy canes on top.