Method
To make the pastry, combine flour, sugar and salt in food processor. Add butter, and while food processor is going, add egg yolks one at a time. Whizz until large clumps form.
Form dough into a ball and flatten into a disk. Wrap in plastic and pop in the fridge for at least an hour. (Let the dough soften slightly before rolling out.)
Roll out dough on lightly floured surface to a round slightly bigger than your tart tin.
Pop dough into your greased tin (one with the removable bottom) and press in to fit nice and snug. Chill while making filling.
To make the frangipane, cream the butter and sugar in a stand mixer. Gradually pop in the eggs, mix until combined well. Fold in the in the ground almonds and flour.
Spread the frangipane filling over the chilled tart base and top with sliced apples. I like to make a pretty spiral, but you can make whatever pattern you like.
Mix sugar and cinnamon in a little bowl and sprinkle over apples.
Bake at 180˚C for 45–50 minutes, or until golden brown.
Chill before removing from tin.