Make the doughnut dough according to the recipe. If you are making traditional doughnuts, use the holes and fry them for 2-3 minutes until golden brown and cooked through. Alternatively, use the full recipe and cut out "holes" (circles), then fry until golden brown and cooked through.
To make the ganache, melt together the chocolate, cream and espresso in a double boiler until smooth.
Combine the sugar and cinnamon then coat the doughnuts with the sugar, while still hot, and serve immediately with the espresso ganache.