32 (about 6 1/2 oz.) chocolate wafers, plus more for garnish (Oreos with the center removed or any other similar chocolate cookie)
1/4 cup powdered sugar
2 tbsp. canola oil
2 tbsp. skim milk
1 tbsp. butter, melted
3 cups red or black raspberries, fresh or frozen (thawed)
2 tbsp. lemon juice
1/4 tsp. salt
2 tbsp. water
1/4 tsp. cream of tartar
1/2 cup superfine sugar, divided
2 large egg whites
Preheat oven to 350 degrees (F). Coat a 9-inch pie pan with cooking spray.
Use a food processor or blender to grind the chocolate wafers, powdered sugar, oil, milk and melted butter until fine. Press the mixture evenly into the bottom and sides of the pie pan. Bake for 12 minutes. Press down any puffed up parts of the crust. Cool on a wire rack for at least 1 hour or until it’s at room temperature.
While the crust is cooling, wash out your blender/food processor. Puree the raspberries, lemon juice and salt in it until smooth. Strain through a fine-mesh sieve into a medium bowl, pressing with a spatula to extract the juice. Throw away the seeds. Set raspberry mixture aside.
Once the crust is completely cooled, fill a large skillet with 1 inch of water and bring to a simmer. Fill a mug with very hot tap water and place an instant read thermometer in it.
In a very clean stainless steel mixer bowl (make sure it doesn’t have a trace of fat or oil in it), combine water and cream of tartar. Add egg whites and 1/4 cup sugar, beat with a whisk until the ingredients are thoroughly combined and the egg whites are completely broken up.
Place the bowl of egg whites in the skillet. Use a rubber spatula to stir the mixture briskly, making sure to scrape the sides and bottom often so that the whites don’t scramble. After a minute, remove the bowl from the skillet, insert the thermometer and tilt the bowl so that at least 2 inches is covered by the egg white mixture. If the temp is less than 160 degrees (F), place the thermometer back in the mug, put the bowl back in the skillet and stir like before until the mixture reaches 160 degrees.
Transfer the bowl to your mixer, beat on medium until the whites reach the soft peak stage which means it bend over when you remove the beater.
Switch your mixer to high speed and continue beating. Add in your remaining 1/4 cup sugar 1 tablespoon at a time, making sure the sugar is fully dissolved before adding more (waiting about 30 seconds should be fine). Once all the sugar is added you may need to stop the mixer for a few seconds to scape down the sides with a clean spatula. Continue beating until the mixture is glossy and stiff (it will hold it’s shape when you remove the beater).
Gently fold the raspberry puree into the egg whites until well combined. Pour into the pie crust. Put the pie on level surface in your freezer and freeze for at least 6 hours or overnight.
To serve, take the pie out of the freezer and let stand for about 10 minutes to soften slightly.