Line a 12-cup muffin tin with paper or silicone liners.

In a microwave-safe bowl, combine the dark chocolate chips and coconut oil. Microwave in 30-second increments at 50% power, stirring between each, until completely melted and smooth.

Gently fold the puffed quinoa into the melted chocolate until well combined.

Spoon about 1 tablespoon of the chocolate-quinoa mixture into the bottom of each muffin liner. Spread it to cover the bottom entirely. Place the tin in the freezer for 10-15 minutes to set.

While the base sets, mix the natural peanut butter, maple syrup, vanilla extract, and a pinch of salt in a small bowl until it thickens into a soft dough-like consistency.

Remove the muffin tin from the freezer. Scoop a small teaspoon of the peanut butter mixture, flatten it slightly, and place it in the center of each hardened chocolate base. Ensure it does not touch the edges.

Spoon the remaining chocolate-quinoa mixture evenly over the top of each cup, ensuring the peanut butter is completely encased. Tap the tin on the counter to level the tops.

Sprinkle with a little flaky sea salt if desired, then return the tin to the freezer for at least 30-45 minutes until the cups are completely firm.

Remove the liners and enjoy cold straight from the fridge or freezer.