Preheat the oven to 400 degrees F. Prick the sweet potatoes a few time with a fork, and wrap in aluminum foil. Place them on a baking sheet and bake for 40 to 50 minutes, until cooked through and fork tender. Once they're soft and fully cooked, scoop the flesh out into a large bowl or medium bowl, and mash until completely smooth. This should result in about 2 cups of sweet potato.

Prepare your pie crust in a pie pan according to your recipe or package instructions. You should par-bake it for about 15 minutes at about 400 degrees F, depending on the recipe, before adding in the pie filling.

Add the melted butter, brown sugar, eggs, evaporated milk, bourbon, vanilla, pumpkin pie spice, and salt to the mixing bowl with the mashed sweet potato. Mix sweet potato mixture together until fully combined and smooth.

Pour the sweet potato filling into the pie shell. Place on a baking sheet and cover the edges with foil to keep them from burning. Bake at 400 degrees F for 15 minutes, then turn the oven temperature down to 350 degrees F and bake for another 30 to 40 minutes, until the edges are set and the center jiggles slightly.

Take out of the oven and cool to room temperature, which should take about an hour. Then, chill for at least two hours and up to 4 days.

To make the brown sugar meringue, start by making a double boiler by bringing 1-2 inches of water to a simmer in a small saucepan.

Put the egg whites, brown sugar and cream of tartar into the bowl of a stand mixer and whisk together. Then, place the bowl over your double boiler, making sure that the bottom doesn't touch the simmering water.

Whisk the whites and sugar continuously until the sugar is dissolved and the mixture has thinned out, about 3 to 4 minutes. You can also use an instant thermometer and whisk until the temperature is 160 degrees F.

Place the bowl back in the stand mixer and put the whisk attachment on. Beat for about 10-15 minutes on high speed, until stiff peaks form and the meringue is no longer warm. If stiff peaks aren't forming after 15-20 minutes, put the bowl in the refrigerator for 10 minutes, and then put back on the mixer and beat until stiff peaks form.

When ready to serve the pie, spread the meringue on top of the chilled pie and pile it high in the center. If you want, use a culinary torch to toasted the edges, making the meringue tinged with golden-brown. Enjoy!