In a medium saucepan, combine the granulated sugar, corn syrup and water. Cook over medium-low heat, stirring until the sugar is completely dissolved, about 3 to 5 minutes. Use a pastry brush dipped in a cup of water to wash down any bit of sugar on the sides of the pot.
Once the mixture comes to a boil, stop whisking and don’t whisk at all during this part to help avoid crystallization. You can brush down the sides of the pot again if necessary, but if shoudn't be needed after this point. Allow to boil on medium-low heat until the mixture turns a deep golden color, about 10-15 minutes, maybe longer depending on your stove. Keep an eye on it, but do not stir. You can tip the pan from side to side, swirling a bit, to help things cook evenly if needed.
Remove the pan from the heat and immediately add in the cream in a slow, steady stream, then the butter. Be careful. The caramel will bubble up quite a bit, creating really hot steam, so be careful with this step. Whisk as you add the cream and butter. Once both are in, place the pan back over medium-low heat to incorporate any unmelted butter. Bring it up to a quick boil, then immediately pour into a clean/ dry bowl. Whisk in the salt and selt aside to cool. *This can be made up to 2 days before assembling the tart, covered and stored in the refrigerator. Soften at room temp or carefully in the microwave when needed.
In a medium saucepan, stir together the cream, milk and brown sugar. Bring to a simmer over medium heat.
In a medium bowl, whisk together the cornstarch, salt, egg and egg yolk until no lumps remain. When the cream/ milk mixture starts to simmer, drizzle it into the bowl with the cornstarch in a thin stream while continuously whisking so you don't cook the eggs. Strain the mixture though a sieve back into the saucepan, and slowly bring to a boil, stirring constantly so the eggs don' t curdle or scorch on the bottom.
As soon as the cream comes to a boil and thickens, remove from the heat. Pour into a heat-proof bowl or container. Stir in the vanilla. Then place a piece of plastic wrap directly on the surface to prevent a skin from forming. Refrigerate until completely chilled before using. *This can be made up to 2 days before assembling the tart.
Preheat the oven to 350F/ 177C.
In a medium-large bowl, combine the flour, finely chopped pecans, confectioner's sugar and salt. Then pour in the melted butter and stir until completely combined and the mixtures resembles wet sand.
Transfer to the tart pan/ pie plate and, using your fingers, press the mixture evenly into the bottom and up the sides of the pan. Chill for 15 minutes, then bake in the preheated oven for 15-20 minutes until golden brown and it no longer looks wet in the center. Set on a wire rack to cool completely. *This can be made the day before assembling/ serving.
In a cast iron skillet large enough to cook the apples in an even layer, add the sliced apples and the water. Cover the pan and cook about 5 minutes until the apples are starting to soften.
Remove the lid, add the butter, brown sugar, cinnamon, vanilla and lemon juice and cook, stirring gently to make sure the apples are evenly coated, about 2-3 minutes, until starting to caramelize. Remove from the heat and pour onto a plate or bowl to cool until needed.
If you made the butterscotch ahead of time, make sure it has softened before beginning. Then spoon about 2 tablespoons into the bottom of the baked and cooled crust. Use an offset spatula or spoon to spread into a thin, even layer.
Carefully transfer all of the brown sugar cream onto the layer of butterscotch and spread into an even layer, creating swirls on top if desired. *I like to create a bit of shallow circle in the middle of the cream (about 2/3's the size if the tart) where we will place the butterscotch on top.
Then spoon some of the butterscotch onto the center of the tart, reserving a little to drizzle on each slice, and use an offest spatula to carefully spread into a circle as you see in the photos. Chill for 2 hours or more.
Then when ready to serve, carefully spoon the spiced apples onto the center of the caramel, creating a pretty look as desired.
Preheat oven to 225F/ 110C.
Arrange apples slices on a parchment-lined or silicon baking mat-lined baking pan.
Bake in the preheated oven until the apples are dried and edges curl up slightly, 45 minutes to 1 hour. (To get them really crispy, turn the oven off at this point and let them stay in the oven another hour.) Then transfer apple chips, using a metal spatula, to a wire rack until cooled and crispy. And arrange on top of the tart however you'd like.
*I left the apples for the spiced apples unpeeled as I wanted the contrasting color on top, but you can peel them if desired.
*If making the apple chips, I suggest starting with those, so they can bake in the oven while the rest if being prepped.
*To make ahead of time: