For the Pie:

1. Pre-heat oven to 350 F. 
2. Stir the pretzel crumbs, graham crumbs, sugar and milk powder together in a large bowl. 
3. Add the melted butter and stir until combined. 
4. Empty the mixture into a 9" pie tin.  Press the mixture into an even layer on the bottom and up the sides of the tin. 
5. Bake for about 9 to 10 minutes.  The crust should firm up a bit and will be very fragrant. 
6. Let crust completely cool before filling. 
7. Scoop the softened Smith's ice cream into the cooled crust.  Using an offset spatula, begin to shape the ice cream so that there is a mound in the center – leaving a bit of room near the top edge of the crust for the meringue topping. 
8. Freeze until solid, or overnight.

For the Meringue Topping:

1. In the bowl of an electric mixer, gently whisk together the egg whites and sugar by hand. 
2. Fill a medium saucepan with a few inches of water and bring to a simmer.  Place the mixer bowl on top of the saucepan to create a double-boiler.  Whisking intermittently, heat the egg mixture until it reaches 150-160 F on a candy thermometer.
3. Once hot, carefully move the mixer bowl back to the stand mixer. Using the whisk attachment, beat the egg mixture on high until stiff peaks (about 8 minutes) and the outside of the mixing bowl returns to room temperature. 
4. Add in the vanilla and mix for about 30 seconds. 
5. Using an offset spatula, spread the meringue on top of the chilled ice cream. 
6. Lightly toast with a kitchen torch or place under the broiler just until browned. 
7. Serve immediately or place back in the freezer.