Apple slab pie

Put the flour, sugar and salt in a food processor, add the cold butter and pulse, about 10 pulses, until the butter is the size of little peas.

Keep pulsing while slowly streaming in cold water until crumbly but holding together when pinched, with visible pieces of butter; do not overwork.

Gather into a disc, cover with plastic wrap and refrigerate about an hour.

Filling: toss the apples with the juice of a lemon, the zest and juice of two clementines, flour, cinnamon, sugar, a pinch of salt and a splash of vanilla.

Topping: cut cold butter into all purpose flour, brown sugar and granulated sugar with a pastry cutter until well distributed.

On a lightly floured surface roll the dough to about the size of the 15 by 10 by 1 inch baking sheet or a little bigger, flouring as needed so it does not stick.

Fit it into the sheet without stretching, since stretched dough shrinks back as it bakes; patch thin spots with dough from elsewhere and cut off the excess with a fluted cutter or a knife.

Spread in the apples and scatter the topping evenly over the top.

Bake at 350 low and slow, about an hour, until bubbly, syrupy and golden.

Let cool completely, slide out onto a parchment-lined sheet, dust the edges with powdered sugar and slice; serve with ice cream.