1. Make the dough by mixing together the flour, 1/3 cup (65 g) sugar, baking powder, and salt in a bowl. Add the olive oil and the eggs, mixing until the dough is smooth.
2. Divide the dough into two pieces, one slightly larger than the other, wrap each in plastic and shape the two dough portions into disks. Chill for at least one hour.
(Dough can be made up to two days in advance.)
3. Wash the chard leaves very well, in several changes of water, until the water is clear and there is no grit in the leaves.
4. Put the chard leaves in a saucepan with a bit of water and a pinch of salt. Cover, and cook the leaves until they’re completely wilted, about 15 minutes.
5. Drain the leaves and run cold water over them, turning them as you rinse. (This ‘shock’ helps set the color.) Once cool, squeeze the leaves very, very firmly to extract as much water from them as possible.
6. Put the raisins in a small saucepan and pour just enough eau-de-vie or brandy over them to cover. Simmer for a minute or two, until the liquor is absorbed. Let cool to room temperature.
7. Chop the Swiss chard and put it into a medium bowl. Coarsely chop the raisins and the pine nuts, and add them to the chard . Stir in the cinnamon, Parmesan, and 1/2 cup (100 g) sugar, then mix in the eggs.
8. To bake the tart, preheat the oven to 350ºF. (180ºC)
9. Lightly butter a 9-inch (23 cm) tart pan with a removable bottom. (No need to butter if it’s a non-stick pan.)
10. Dust both sides of the larger pieces of dough and roll it between two large sheets of parchment paper. About halfway through rolling, peel away the parchment and re-dust both sides of the dough with flour, then continue to roll the dough until it’s the size that will fit into the bottom of the tart pan and go up the sides.
11. Peel away the top piece of parchment and carefully overturn the dough on to the tart pan. Peel away the other piece of parchment and use your fingers and the heel of your hand to smooth the dough into place and even it out.
(I use my thumbs and heel of my hand to make sure it goes up the sides as best as possible.)
12. Spread the filling into the tart pan over the dough, then peel and thinly slice the apples, and lay them in an even layer over the Swiss chard filling.
13. Roll out the other disk of dough as you did the lower one, between two parchment paper sheets, and transfer it to the tart pan to cover the tart filling.
14. Use your fingers to seal the dough at the edges to enclose the filling. A few gaps are normal.
15. Bake for 30 to 40 minutes, until the dough is golden brown on top. Remove from the oven and dust the top with powdered sugar.
Let cool before slicing.