- Bring 4 cups marshmellows,2 cups shugar,1 cup heavy cream,4 tablespoons butter and a pinch of salt to a simmer in a large pot over high heat.
- Cook,stirring,until melted,5 minutes.
- Remove from the heat and stir in 3 cups white chocolate chips and 2 teaspoons peppermint extract.
- Pour into an oiled foiled-lined 9-by-13 inch baking dish.
- Top with crushed candy canes.
- Let cool;cut into squares.
- Melt the 1 1/2 chopped mint chocolate in the microwave, stirring every 30 seconds.
- Dip 12 mint-chocolate sandwitch cookies halfway in the melted chocolate and arrange on a parchment-lined baking sheet.
- Refrigerate until set, about 30 minutes.