Heat coconut oil and carob chips in the microwave for 20 seconds at a time until melted, stirring to combine and mixture is smooth.
Line a muffin pan with paper cupcake liners.
Using a small spoon, pour the melted carob into the liners about ¼ to ⅓ of the way full. Using the back of the spoon, push the melted carob up the sides of the paper liner to coat the sides. Reserve about half of the mixture for the top of the cups.
Place the muffin pan into the fridge or freezer for a few minutes to harden the carob layer.
Melt the peanut butter in the microwave for 20 seconds at a time until it becomes more liquid.
Remove the muffin pan from the fridge and spoon the melted peanut butter onto the hardened carob.
Return the muffin tin to the fridge for a few minutes, until the peanut butter has solidified.
If the leftover carob has hardened, melt it again. Spoon the remaining carob onto the top of the peanut butter.
Place in the fridge or freezer for a few minutes until hardened.