To poach the pears, place the water, sugar, vanilla and thyme branches into a medium saucepan and bring to a boil. Meanwhile, squeeze the lemon juice into a shallow bowl. Slice the very bottom and very top off each pear and peel. Halve the pears from stem to bottom. With a measuring spoon or melon-baller, scoop out the core of the pear including the vein that runs from top to bottom. As each half is prepared, place in the lemon juice and rub all over to coat.
When the syrup has boiled, turn heat down so the liquid simmers and add the pear halves. Cook for approximately 20 to 25 minutes or until the tip of a sharp knife slides easily into the inside of one of the pear halves. Let cool in saucepan. The pears may be made two days in advance and stored covered in the fridge.
Thaw the puff pastry at room temperature for 45 minutes. Meanwhile,
prepare the almond cream. With an electric mixer on high speed, beat the margarine in a medium bowl until soft. Add the sugar, almond flour and flour and beat until creamy. Add the egg and vanilla. Turn speed to high and beat for one minute, until the mixture is light and airy. Cover and place in the fridge until ready to assemble the cake, up to three days in advance.
To shape the cake you will need two dinner plates or round baking pans, one that is about 8 inches diameter and one that is 10 inches diameter. Place a piece of parchment on the counter and sprinkle with some flour. Unroll one sheet of puff pastry and use a rolling pin to roll out to smooth out the lines, until it is larger than the 10-inch plate. Place your plate over the pastry and run your knife around the plate to cut out a circle, discarding the trimmings. Take your 8-inch pan or plate and press on top of the pastry to mark a circle on the pastry, or use a dull knife to score a circle, without cutting through. Set aside.
Take another piece of parchment and roll the second sheet of pastry as the first. Place the 10-inch plate on top and cut out another 10-inch circle. Make sure to peel up the dough and sprinkle some flour underneath so the dough does not stick to the parchment; you have to lift it up later.
Remove the almond cream from the fridge. Lift the pear halves out of the syrup and place on paper towels to dry. Slice the pears the long way into ¼-inch slices.
Brush the beaten egg on the 2-inch border made between the scored circle and the outer edge. Using a silicone spatula spread the almond cream on the circle inside of the egg-brushed border (not on the border). Try to spread it as evenly as possible. Place the pear slices cut side down on top of the almond cream, overlapping if necessary to use up most of them. Place your hand under the parchment of the second pastry circle and lift it up and flip it over on top of the almond cream. Peel off the parchment and stretch the dough so that you can press the edges of the two pastry sheets together to seal the top dough to the bottom dough. Pinch to seal tightly. Place your 8-inch plate or pan on top and use the back of a knife to score but not cut a circle around the filled center so you have a border around the part that holds the cream filling. Use a knife to cut a scalloped pattern on the border, careful not to cut beyond where the two pastry sheets are sealed together. Use a knife to mark but not cut a pattern on top, by holding the tip of the back of the knife in the center and marking curves from the center to the inside border. Brush the top with the beaten egg. Reserve the egg to brush the top again before baking. Place the pan with the cake into the freezer for 20 minutes.
Preheat oven to 450°F. Remove the cookie sheet from the freezer and brush the dough again with the beaten egg. Sprinkle the top with the two teaspoons sugar. Bake for 15 minutes. Reduce the temperature to 400°F and bake another 25 to 30 minutes, or until browned. Serve warm or at room temperature.
reprinted from The Holiday Kosher Baker (Sterling 2013)