2) Process the chocolate wafers in a food processor with the butter, sugar, coffee and salt until fine. Evenly press into the prepared dish covering the bottom completely. Bake until the base sets, about 15 mins.
For the filling:
1) Put the chocolate in a medium microwave-safe bowl; heat at 75 percent power until softened, about 2 mins. Stir, and continue to microwave until completely melted, up to 2 mins more. (Alternatively put the chocolate in a heatproof bowl. Bring a saucepan filled with 2cm 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.)
2) 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.
3) Pour the filling evenly over the base. Bake until the filling puffs slightly around the edges, but is still a bit wobbly in the centre, about 25 to 30 mins. Cool on a rack.
For the glaze:
1) Put the chocolate, butter and golden syrup in microwave safe bowl. Heat the glaze in the microwave at 75 percent power until melted, about 2 mins. Stir the ingredients together until smooth; add the sour cream.
2) Spread the glaze evenly over the warm cake and scatter the crushed candy canes over top. Cool completely, then refrigerate overnight.
3) Cut into small bars or squares and serve chilled or at room temperature. Store the cakes covered in the refrigerator for up to 5 days.
Cook's Note: To crush the candy canes, remove the wrappers and place in a resealable plastic bag. Use a rolling pin to roll and break the candy up into small pieces, about 0.5cm or so.