Combine chocolate wafers and 2 candy bars in a blender; pulse into fine crumbs.
Place about 1 cup of crumbs in an 8-inch pie pan. Pour in melted butter; press down with your fingers or a fork to make the crust.
Bake crust in the preheated oven until fragrant, 7 to 9 minutes. Let cool.
Blend cream cheese in a large bowl until almost smooth. Pour in condensed milk and mix until creamy. Add lemon juice and vanilla extract; mix until filling thickens slightly, 4 to 6 minutes. Fold in 1/2 cup crushed candy bars. Pour over crust and smooth the top.
Refrigerate cheesecake until set, at least 4 hours but preferably overnight.
