1.Lightly grease a 9x9 inch pan lined with wax paper, smoothing out all the wrinkles. Set aside
2.Place the semisweet chocolate and 1 tsp canola oil in the top of a double boiler over just barely simmering water, stirring frequently and scraping down the sides with a rubber spatula to avoid scorching.
3.When the chocolate is melted stir in ¼ tsp of the peppermint extract. Pour the melted chocolate into the prepared pan and spread evenly over the bottom of the pan. Sprinkle half of the crushed peppermints over the chocolate layer. Refrigerate until completely hardened about 1 hour.
4.Repeat the same steps with the white chocolate (melt in a double boiler, add the peppermint). Once melted pour directly over the chocolate layer and spread evenly. Sprinkle the remaining crushed candy over the top and gently press in. Refrigerate until completely hardened. Remove from the pan, break into small pieces and serve.