Get out a standard 9” (23cm) tart plate with a removable bottom. It should be one that's safe to move from the fridge to a hot oven. Do not grease it.

To the bowl of a food processor fitted with an S-blade, add the flour, granulated sugar and salt. Pulse a few times.

Add the butter and pulse. Pulse just until you have pea-sized bits of butter. Don’t overprocess! Stop pulsing.

Evenly drizzle the vanilla extract and apple cider vinegar over the top.

Turn on the lowest speed and pour in 2.5 tablespoons of water. The amount of water you need will depend on how cold your ingredients, kitchen, etc. are. I’ve made this several times with the same brand of ingredients, and have needed between 2.5 and 5.5 tablespoons.

Process very briefly until it looks like it’s coming together. It’ll look shaggy and not like a uniform ball. Pinch some together. If it stays together without being crumbly, it’s ready. You don't want to add too much water. More water than necessary = non-flaky tart crust. If you think it needs a bit more water (it almost certainly will), add more water, 1 teaspoon at a time. If you think you can form a disc with it without it falling completely apart into a thousand crumbs, that’s another clue it’s ready.

Place the dough in the center of a large piece of plastic wrap and wrap it up into a flat disc, about 1” (2.5cm) or a little less. If you can’t form a disc because it’s nothing but crumbs, it needs a little more water.

Refrigerate for at least 45 minutes and up to 2 days.

Place a baking sheet on the baking rack (one in the lower third of the oven) that will fit your tart pan. This is for the very unlikely case that something spills over and for a crisper crust bottom.

Preheat the oven to 350 °F (175 °C).

Very lightly flour a piece of parchment paper and place the unwrapped dough on there. Sprinkle a tiny bit of flour over the top of the dough.

Place the plastic wrap or another piece of parchment paper on top of the dough and roll it out so that it’s about 1/3” (.84 cm) wider than your tart pan.

Remove the piece of plastic wrap or parchment covering the crust, place the ungreased tart pan on top of the dough, and then flip over the dough and pan. Press the dough down around the edges at the bottom of the pan and then remove the piece of parchment paper.

Trim away any dough hanging off the edges and use it to thicken the top part of the dough, if necessary. It shouldn’t be uniform in thickness around the edge.

Cover with plastic wrap or the piece of parchment paper and place in the freezer for 15 minutes or in the fridge for 30 minutes, while preparing the filling.

In a large mixing bowl, stir together all filling ingredients except for the pecans, sprinkling on the cornstarch, rather than plopping down a big clump. If there are any eggy bits that aren't coming out, remove them or they’ll bake up ugly.

Once combined, stir in the pecans.

Pour the filling into the unbaked crust and bake for 35-40 minutes or until the middle is set. It’ll have risen a bit but will settle back down as it cools.

Let cool completely, about 2 hours, and then refrigerate for at least 2 more.

Cover and refrigerate any leftovers for up to 4 days or wrap, put in a Ziploc bag and freeze for up to 3 months.