Line a muffin tin with paper or silicone liners. The recipe should make about 10-12 peanut butter cups depending on how thick you make your layers.Melt carob chips and coconut oil for 1 minute in a double boiler, stir and continue heating on 30 second intervals, until carob chips have melted and carob is smooth.Using a spoon pour enough carob (about 1-2 teaspoons) to cover the bottom of the liner into each liner. Place tray into the freezer for about 5-10 minutes for the carob to set.In another bowl, add peanut butter, agave and coconut oil. Stir over boiling water until mixture is slightly melted and pourable. Stir to combine.Remove cups from the freezer and pour peanut butter mixture evenly over each cup. Place back in the freezer to set for about 5 minutes.Pour remaining carob over each cup, using just enough to completely cover the peanut butter layer. At this point you can also sprinkle flaked sea salt on top of the carob if you want!Place tin back in the freezer for about 30 minutes to an hour to set completely. Remove from freezer and store in the refrigerator until ready to serve.