Walnut Gateau Breton

Directions

1. 1
   1.
2. 2
   Preheat the oven to 300F/150C/gas 3/4.
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   Butter and lightly flour a 9-inch/23-cm cake pan.
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   2.
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   Place the walnuts and 2 tablespoons of the sugar in the bowl of a food processor and grind so that most of the walnuts are finely ground but not anywhere near a paste.
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   3.
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   In a large bowl, whisk together 6 of the egg yolks and the remaining 1 cup 2 tablespoons sugar until the mixture is blended, just a few minutes; there is no need to use an electric mixer here.
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   It will be thick and yellow but shouldn't form a ribbon.
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   Slowly whisk in the walnuts and sugar, then the butter.
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    Sift the flour over the mixture and whisk it in just until the mixture is homogeneous.
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    Don't overmix the batter or the cake will be tough.
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    4.
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    Whisk together the remaining egg yolk and 2 teaspoons water, to make an egg glaze.
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    5.
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    Turn the batter, which will be quite stiff, into the prepared pan and smooth it out.
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    Lightly but thoroughly paint it with the egg glaze.
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    Using the back of the tines of a fork, deeply mark a crisscross pattern in the top of the cake, going three times across it in one direction, then three in another.
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    (The marks in the cake will fade, leaving just their trace on the top of the cake.)
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    6.
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    Bake in the center of the oven until the cake is deep golden on the top and springs back slowly but surely when it is touched, about 1 hour and 15 minutes.
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    Using a knife or cake tester isn't recommended as it always comes out looking slightly damp because of the amount of butter in the recipe.
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    7.
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    Remove from the oven and transfer the cake to a wire rack, and let it cool for about 10 minutes before turning out of the cake pan.
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    Let it cool thoroughly before serving.