Preheat oven to 180 degrees C. Line baking trays with baking paper or aluminium foil.
In a large glass or metal mixing bowl, beat egg whites and salt until foamy. Gradually add sugar, continuing to beat until whites form stiff peaks. Fold in the vanilla and chocolate chips. Lastly, add peanuts. Spoon onto the prepared baking trays.
Place the biscuits into the preheated oven, shut the door and turn off the oven immediately. Let biscuits sit in the turned off oven for 5 to 6 hours or overnight.