Prep: Preheat the oven to 350F and generously grease an 8" tart or pie pan with non-stick cooking spray; set aside. Make sure you have enough room in your fridge or freezer to be able to store the pie on a level surface.
Crust: Add the Oreo cookies to a food processor with a S-blade attached. Pulse a few times to get a crumbly texture, then add in the melted coconut oil. Process for 45 to 60 seconds, scraping the sides as necessary. A uniform ball of dough that is slightly crumbly should form. Press the dough into the tart dish - I like to use a flat-bottomed glass to really pack it in. Bake for 10 to 12 minutes, then set aside to let cool.
Chocolate Layer: Melt the chocolate using either the microwave or a double boiler (see notes). Use a spatula to spread most of the chocolate layer across the bottom of the pie dish, saving 2 to 3 tablespoons for decoration in step 5.
Peanut Butter Filling: In the meantime, add the tofu, peanut butter, coconut oil, maple syrup, vanilla, lemon juice, and salt to the food processor and process for at least 60 seconds, until the mixture is thoroughly whipped and smooth. Pour this mixture over the pie base and use a spatula to smooth out the top.
Chocolate Drizzle: Drizzle the remaining melted chocolate over the pie.
Set & Serve: Place the pie in the fridge overnight until set, or for at least 8 hours. You can also place the pie in the freezer for at least 4 hours and thaw before serving. Once set, serve as desired; leftovers will keep in the fridge for up to 5 days, or in the freezer for up to 2 months.
Crust Substitutions: replace the vegan butter with equal parts refined coconut oil and 1/4 teaspoon kosher salt.
Melting Chocolate in the Microwave: Chop the chocolate roughly into small chunks and place in a microwave-safe bowl. Microwave for 60 seconds, then use a clean and dry spatula to stir well; continue to microwave the chocolate in 20 second intervals, pausing to stir well. Once the chocolate is 80% melted, remove from the microwave and stir with the spatula until completely melted.
Melting Chocolate with a Double-Boiler: Fill a sauce pan with 1-2″ of water, then place a glass bowl over the top. Bring the water to a boil over high-heat, then reduce to medium-low heat. Chop the chocolate roughly into small chunks and place in the glass bowl. Allow the heat from the bowl to melt the chocolate, using a clean and dry spatula to stir well. Continue warming the chocolate until it is 80% melted, then carefully remove the bowl from the pot. Stir with the spatula until completely melted.
Crust Variation: for a refined sugar-free crust, blitz 3 3/4 cups cereal, 3 tbsp cocoa powder, 4 1/2 tbsp maple syrup, and 1/4 cup + 2 tbsp peanut butter together in a food processor. Press into the pie base and proceed with the recipe as written.
Peanut Butter: if your peanut butter is unsalted, use 1/2 teaspoon of salt in the PB filling instead of 1/4 teaspoon.