Preheat oven to 375

Combine the graham cracker crumbs, butter, and salt in a bowl

Mix to combine well

Press the mixture into a 9 inch tart pan or pie dish; make sure to press the mixture in well to that the graham crackers stick together

Bake in the oven for about 10-12 minutes

Cool to room temperature

Reduce the oven temperature to 325 degrees

Combine the sweetened condensed milk, zest, lime juice, egg yolks, and sour cream in a bowl and mix well with a whisk

Pour the filling into the cooled pie crust and bake for 15-17 minutes, or until the center is set and still a slightly jiggly

Allow to cool

For the meringue place the sugar and egg whites into a heat proof bowl (I usually use a mixing glass bowl) and place over a pot with a small about of simmering water, making sure the water isn’t touching the bowl

Use a whisk to mix the egg whites and sugar continuously until the sugar has devolved into the egg whites; You will know when it is ready by rubbing some of the mixture between your fingers, and if it isn’t grainy, then it is ready.

Place the egg white mixture into the bowl of a stand mixer with a whisk attachment (this could also be done with the hand mixer, it may just take longer)

Whisk in the stand mixer for about a minute and add in a pinch of salt and the cream of tarter

Whisk for another 5-8 minutes until the mixture has doubled in size and looks like marshmallow fluff and holds a stick peak

Place into a piping bag (or a plastic bag works too) and pipe large mounds of meringue on the top of the prepared pie

Use a kitchen torch to add some toasted parts onto the meringue, if you don’t have a kitchen torch, you can carefully place the pie into the oven under the broiler, making sure to keep your eye on it so it doesn’t burn (it can burn easily, like marshmallows over a flame)

Place the pie in the fridge for a few hours before serving

***Note: if you have extra meringue, you can make little meringue cookies by piping little dollops onto a baking sheet lined with parchment paper, and bake at 200 degrees for about a half hour, or until they can pull away from the sheet. Then, turn the oven off and allow them to cool completely for a few hours.