Maple sugar is a granulated sugar made from dehydrated maple syrup. You can find it on Amazon or in many Whole Foods Stores. Coconut sugar is becoming more widely available. It is a fine substitute, but it will make the tart a much darker shade of golden than the maple sugar.
For the paleo pie crust:
- 2 cups finely ground almond flour (I used Bob’s Red Mill Superfine Almond Flour)
- 1 cup arrowroot starch
- 2 tablespoons maple sugar (or 3 tablespoons coconut sugar)
- 1 1/2 tablespoons ground chia seeds (I used white chia seeds)
- 1/2 tablespoon ground flax (I used golden flax seeds)
- 2 teaspoons baking powder
- 1/4 teaspoon salt
- 4 tablespoons cold unsalted butter, ghee, lard, duck fat, refined coconut oil, or sustainable palm shortening
- 1 large egg
- 1 egg yolk
- 3 to 6 tablespoons ice water
- Extra arrowroot or tapioca starch for shaping and rolling
For the apple filling:
- 6 medium baking apples (I like a mix of Granny Smiths and Honeycrisp)
- 2 tablespoons unsalted butter, ghee, refined coconut oil, or palm shortening
- 2 tablespoons maple sugar (or three tablespoons coconut sugar)
- 2 tablespoons lemon juice
- 1 tablespoon vanilla extract (optional)
- Zest of one lemon
1 Make the pie crust: Combine the almond flour, arrowroot, maple sugar, chia, flax, baking powder, and salt to the bowl of a food processor and pulse 5 to 6 times to combine. Add the butter and pulse another 4 to 5 times until the mixture starts to look like sandy, pea-sized gravel. Add the egg and egg yolk, then sprinkle 3 tablespoons water evenly over the top of the dough. Pulse a few times until the mixture just starts to clump together and form a ball.
2 Chill the crust: Turn the pastry dough out onto a cutting board and use your hands to shape it into a chubby disk. Wrap tightly in plastic and refrigerate for at least one hour or up to three days.
3 Roll out the crust: When ready to bake the tart, lay a sheet of parchment on your counter or other flat surface and sprinkle with arrowroot or tapioca starch. Place the chilled pie dough in the center of the parchment and roll into a circle about 12 inches in diameter.
4 Transfer the crust to the tart pan: Flip your tart pan upside down and place it in the center of the rolled out pastry dough. There should be at least 1 1/2 inches of pie dough showing around the edge. Carefully, slide one hand palm side up under the parchment and place the other hand on the tart pan. Quickly, and with great confidence, flip the whole thing over.
Gently ease the crust into the tart dish and press it into the corners. Peel back the parchment and discard. Your pastry dough may break, but just press the cracks back together if it does. Use a paring knife to trim away the excess dough and then prick the bottom of the tart all over with the tines of a fork.
5 Place the tart shell in the freezer to chill while you prepare the apples.
6 Preheat oven to 350F.
7 Prepare the apples. Peel the apples and halve them lengthwise. Use a melon baller, paring knife, or small spoon to remove the core, seeds, and stem. Slice the apples very thinly (ideally 1/8-inch thick) using a chef's knife or mandoline.
8 Prepare the glaze: In a small saucepan, melt butter (or other fat) with the sugar, lemon juice, and vanilla over medium heat. Whisk to combine while bringing to a simmer. Keep whisking until all sugar is dissolved.
9 Assemble the tart: Find a few of your thinnest apple slices and set them aside. Remove the tart shell from the freezer and begin laying the apple slices in concentric circles, starting from the outer edge of the crust and spiraling inward.
When you get to the center, take your thinnest apple slices and fold them gently to form the center of the pattern. (You might have some apple slices leftover.)
Sprinkle the lemon zest evenly over the tart. Drizzle about half of the glaze evenly over the tart. (I dipped a pastry brush in the glaze and let it drip onto onto the apples.)
10 Bake the tart for 40 minutes, turning the pan halfway through baking.
11 Brush the rest of the glaze over the apple slices. Return to the oven and bake for 5 more minutes.
12 Serve warm or at room temperature.