Preheat oven to 350 degrees F. Line an 8-inch square baking dish with foil.

For the crust: Process the chocolate wafers in a food processor with the butter, sugar, coffee, and salt until fine. Evenly press the crust into the prepared dish covering the bottom completely. Bake until the crust sets, about 15 minutes.

Meanwhile, make the filling: Put the chocolate in a medium microwave-safe bowl; heat at 75 percent power until softened, about 2 minutes. Stir, and continue to microwave until completely melted, up to 2 minutes more. (Alternatively put the chocolate in a heatproof bowl. Bring a saucepan filled with an inch or so of water to a very slow simmer; set the bowl over, but not touching, the water, and stir occasionally until melted and smooth.)

Blend the cream cheese, sugar, and sour cream together in the food processor until smooth. Scrape down the sides, as needed. Add the eggs and pulse until just incorporated. With the food processor running, pour the chocolate into the wet ingredients and mix until smooth.

Pour the filling evenly over the crust. Bake until filling puffs slightly around the edges, but is still a bit wobbly in the center, about 25 to 30 minutes. Cool on a rack.

For the Glaze: Put the chocolate, butter and corn syrup in microwave safe bowl. Heat glaze in the microwave at 75 percent power until melted, about 2 minutes. Stir the ingredients together until smooth; add the sour cream. Spread glaze evenly over the warm cake and scatter the crushed candy canes over top. Cool completely, then refrigerate overnight.

Cut into small bars or squares. Serve chilled or room temperature.

Store cookies covered in the refrigerator for up to 5 days.

Cook's Note: To crush the candy canes, remove wrappers and place in a resealable plastic bag. Use a rolling pin to roll and break the candy up into small pieces, about 1/4 inch or so.