Preheat oven to 350 degrees. Spray silicone tart baking sheet with nonstick spray. Place onto baking sheet. Set aside.
Process Oreo cookies until they turn into fine crumbs. Add melted butter and stir together until combined. Spoon about 2 tablespoons in each tart shell. Using a shot glass or small glass, press crumbs into shell and up the sides.
Bake in preheated oven for 5-7 minutes. Remove from oven and let it cool completely.
Add heavy cream and granulated sugar to a bowl fitted for a stand mixer. With the whisk attachment, beat cream until stiff peaks form. Remove whipped cream and place into a small bowl. Add cream cheese, almond butter, and powdered sugar to bowl. Using a paddle attachment, mix ingredients until combined.
Gently fold in whipped cream so it doesn't deflate. Scoop about 1/4 cup of mixture into each tart shell. Using the back of a spoon, spread filling to the edges of the shell.
Melt 4 ounces of dark chocolate and drizzle over each tart. Top with chopped chocolate almond bark pieces. Place tarts into fridge to set for 1 hour and then serve.