Line a metal muffin pan with paper liners or use a silicone muffin pan (no need to line the silicone pan).
Start with the oat layer. Mix quick-cooking oats, honey, peanut butter, and chopped peanuts in a bowl until combined. If it’s too dry, add 1 to 2 teaspoons of water. Press about 2 tablespoons of the oats into the bottom of each muffin cup.
For the chocolate layer, melt the dark chocolate and coconut oil in a microwave-safe bowl in 20-second increments until smooth. Pour 2 teaspoons of melted chocolate onto the oat layer in each cup. Swirl the pan to spread the chocolate evenly. Freeze for 5 minutes.
Make the peanut butter layer by microwaving peanut butter and coconut oil for 15 seconds. Stir and add 2 teaspoons of the mixture onto the chocolate layer. Swirl again and sprinkle mini chocolate chips on top of each cup.
Freeze the muffin tin for 30 minutes to an hour until set.
Once firm, remove the oat cups from the muffin pan and store them in a freezer bag in the freezer.