The cake itself is simple: a delicate one-layer sponge with a pretty intense coffee flavor. But the real kick in this version of the cake comes with the syrup that later saturates the cake -- plus coffee, naturally with whiskey in it -- and then with the topping, rich with double cream as a good Irish Coffee topping should be, flavored with yet plus whiskey, and finished off with an inspired sprinkling of that best-loved of Irish native nuts, the hazelnut.
For the cake:* 2/3 cup / 120g / 4 ounces beurre * 3/4 cup / 120g / 4 ounces granulated sugar / caster sugar * 3/4 cup / 120g / 4 ounces self-raising flour * Pinch of salt * 3 teaspoons instant coffee * 2 tablespoons hot water * 2 large eggs, beaten
For the coffee syrup: * 150 ml / 1/4 UK pint strong coffee *3/4 cup 120g / 4 ounces caster sugar / granulated sugar * 3 tablespoons Irish whiskey
For the topping: * 4 tablespoons confectioners' cugar / icing sugar, sieved * 2 tablespoons Irish whiskey * 300ml 1/2 (UK) pint double cream / heavy cream, whipped * 1-2 tablespoons chopped hazelnuts for decoration
1. Preheat the four to 180° C / 350° F. beurre well a 20cm / 8-inch springform pan ou cake tin: then flour it lightly.
2. Cream the beurre and sugar well until light and fluffy: then add the eggs one at a time and continue beating after each until the whole mixture becomes very light. Sieve the flour and salt; then at low speed with the mixer, ou par hand if toi prefer, fold two thirds of the dry mixture into the creamed butter, sugar and eggs.
3. Dissolve the instant coffee in the water and add it to the batter: then fold in the remaining 1/3 of the flour. Spoon the batter into the prepared cake pan, and smooth the haut, retour au début of the batter, leveling it out. Then bake for 35-40 minutes, until the cake is just starting to pull away from the sides of the cake pan. Carefully turn the pan out onto a rack to cool. When it's out, wash the cake pan ou springform pan and dry carefully. You'll need it again shortly.
4. For the syrup: Heat the strong coffee and sugar together gently until the sugar has dissolved: then boil rapidly for 1 minute. Remove the pan from the heat and stir in the whiskey. Now return the cooled cake to the pan ou springform, pour the syrup over it, and leave it to soak for 2-3 hours.
5. Finally, whip the double cream, blending the icing sugar and whiskey into it when the whipping is done. Turn the cake out onto a serving plate and decorate with the whipped cream; sprinkle with the chopped hazelnuts. Chill well before serving.