Ingredients
Method
1.Grind hazelnuts in a liquidiser or small electric grinder, but be careful not to overwork them because they can become oily; a few smallish, chunky bits are fine.
2.Separate eggs, putting the yolks in the bowl of a cake mixer and the whites in a separate grease-free bowl (if you don’t have a cake mixer use a hand-held electric beater, or a large whisk and lots of elbow grease).
3.Whisk egg yolks briefly to break them up, then with the machine running, gradually add the caster sugar, then the lemon juice. Whisk until the mixture is like a thick, pale cream and will hold a trail (like a cascading ribbon) when you lift up the beaters.
4.Blend in lemon zest, ground hazelnuts and semolina and rest mixture for 15 minutes to soften the semolina.
5.Meanwhile, preheat oven to 180°C, setting the oven shelf just below the middle of the oven. Prepare a deep, 20cm-wide cake tin by lightly brushing the insides with melted butter, lining the base with baking paper and brushing that with butter also. Sprinkle in a little flour, shake it around the tin to coat the sides and bottom, then tip upside down and tap out excess flour.
6.Peel pears and slice flesh thinly, discarding any cores or fibrous matter. Stir into cake mixture.
7.Whip egg whites with grease-free beaters until they resemble a thick, dense snow which is able to hold its shape (don’t make them stiff as for a meringue or they will be difficult to fold in). Using a large spoon, gently mix in 1 large tablespoon of egg white into cake mixture to lighten it, then add the rest and carefully fold it all together, taking care not to knock out the air. Pile mixture into tin, and tilt tin to encourage it to settle evenly.
8.Bake the cake for 30-35 minutes, until a good, even, golden-brown colour and slightly springy to the touch. Remove from the oven and cool in the tin away from draughts for 15 minutes.
9.Turn it out onto an oven sheet lined with baking paper and carefully peel away the paper. Cover with a clean piece of baking paper and a cake rack and deftly turn it over so the top of the cake is upright. Cool.
10.To finish, either dust with icing sugar, or top with dollops of lightly whipped, sweetened cream. If using the extra toasted, skinned hazelnuts, coarsely chop a few of them and scatter cake with these and whole nuts.
