• Prepare a 2-crust pie dough. Roll out a little more than half the dough 1/4-inch thick and place in a tart pan. Allow the dough to hang over the pan about 1/2-inch and trim the rest away. Crimp the edge of the dough to form a thicker edge around the top of the pan.
• Partial blind bake the bottom crust in a 400°F oven for 8-10 minutes, until the dough is set but not browned—the edges may lightly brown, and the bottom of the pie crust will not look raw or wet. Remove from the oven and set aside.

FOR THE APPLE FILLING

• In a mixing bowl, toss the sliced apples with the lemon juice and zest to coat.
• Mix the sugar, flour, cinnamon, and cardamom in a separate bowl and toss with the apples until evenly coated.
• Arrange the apples in the prebaked crust and dot with butter.
• Roll out the remaining pie dough 1/4-inc thick. Using a knife or a decorative pastry cutter, cut the rolled-out top crust dough into 7-8 1-inch-wide strips (shorter edge strips can be molded together). Using a spatula or pastry scraper, lift the dough strips and place 3 or 4 evenly over the pie filling. Repeat with 3 or 4 strips angled in the opposite direction. Pinch or press the ends of the dough strips against the edge of the bottom crust to secure.
• Brush the cream on the pastry crust and sprinkle with the raw sugar.
• Set the tart in the oven and bake for 35-40 minutes at 400°F until the filling is bubbly and the crust is golden brown. TIP: Since the tart pan is not sealed on the bottom, it is helpful to wrap foil around the bottom to catch any drips in the oven, or set a sheet of foil on the oven rack directly under the rack the tart is baked on.
• Transfer the tart to a cooling rack to cool for about an hour until the outer rim of the pan can be safely removed.

FOR THE SALTED CARAMEL SAUCE

• Heat the cream in a saucepan or microwave (30 seconds) just until warm but not hot. Make sure the butter is at room temperature and cut into 6 pieces.
• In a heavy 3-quart saucepan, add the water and lemon juice to the sugar and stir to wet some of the sugar. Cook over medium heat and allow the suger to melt and bubble until it turns a medium amber color, about 10 minutes. Be careful to watch it and remove from heat if the color goes beyond a deep gold or smells like it's burning.
• Once sugar is gold in color, add the butter and cream—be careful in this step because the caramel will bubble rapidly—stir to combine with a heat proof spatula or wooden spoon. Let the caramel cook and bubble for 1 more minute (no need to stir).
• Remove from heat and stir in the salt. The caramel will thicken as it cools.
• Once the tart is cooled and sauce is cooled, but still easily stirable, drizzle the sauce over the tart. Slice and serve tart with more sauce, as desired.