Whisk together the egg yolk, heavy cream, and vanilla extract in a bowl. Set aside.

In a spice grinder, grind Sucanat until fine and powdery.

Place Sucanat, flour, and salt in the bowl of a food process. Pulse a few times to ensure that they are mixed.

Scatter chilled butter cubes on top and pulse until mixture resembles coarse cornmeal, 15 (1-second) pulses.

While the food processor is running, slowly pour the egg mixture through the tube and process until the dough barely comes together, about 12 seconds.

Transfer the dough onto a clean surface and shape into a 6-inch disk.

Wrap it tightly with stretch film and place in the fridge for at least 1 hour. You can make this 2 days in advance and keep it in the fridge until you are ready to use. It can also be frozen up to 2 months.

Remove the tart dough from the fridge and let it sit on the counter for 10 minutes.

On a lightly floured surface, roll it onto an 11-inch circle and transfer it to a 9-inch tart pan with a removable bottom. Gently ease the dough into the pan by lifting edges of the dough with your hand while pressing into the corners and the fluted sides of the pan.

Run your rolling pin over the top of pan to remove any excess dough. Loosely cover the tart pan with stretch film and place in the fridge for 30-minutes. (Dough-lined tart pan can be wrapped tightly in plastic and refrigerated for up to 2 days or frozen up to 1 month)

Pre-heat the oven to 375 Degrees.

Place the dough-lined tart pan on baking sheet, line with a double layer of aluminum foil, making sure to cover the edges to prevent from burning, and fill with pie weights (or dried beans).

Bake until the crust is golden brown, for 30 minutes, rotating pan halfway through the baking to ensure even baking.

Remove pie weight and let the crust cool on the kitchen counter.

Heat Sucanat, water, and salt in a small-size tall-sided saucepan over medium-high heat, stirring occasionally until Sucanat fully dissolves.

Reduce the heat to medium and simmer, stirring constantly, until it is slightly thickened (vigorously bubbling) and registers 260 F degrees. This should take 10-12 minutes.

Off the heat, carefully pour in the heavy cream and swirl to incorporate. Be careful as it will vigorously bubble. Once the bubbling subsides, whisk in butter, bourbon (if using), and vanilla extract.

Stir in the nuts.

Pour warm filling into the cooled crust. Using the back of a spatula, evenly distribute the mixture.

Set tart-pan on a baking sheet and bake until caramel is vigorously bubbling, about 10 minutes.

Let it cool for at least 2 hours and then sprinkle it with sea salt.

When ready to serve, carefully remove the tart from the pan, slice and serve with a scoop of your favorite ice cream or just by itself.