In a bowl, mix peanut butter and maple syrup.
Add oats and mix until well combined.
Press oat mixture into silicon molds evenly using a spoon or cookie scoop (about 2 tbsp per base).
Add a dollop of peanut butter on top and freeze for 20 minutes.
Meanwhile, melt dark chocolate in the microwave with a bit of oil.
Once firm, pour melted chocolate over each oat cup and freeze for an additional 20 minutes.
Remove from liners, sprinkle with flakey sea salt if desired, and enjoy!