Arrange your mini muffin liners on a plate to get started.

In a medium bowl, combine the peanut butter, vanilla, and powdered sugar, mixing until smooth and fully blended.

In a separate microwave-safe bowl, add the chocolate chips and coconut oil. Heat in the microwave in 15-second intervals, stirring between each round, until the chocolate is completely melted and smooth.

Spoon about 1½ teaspoons of melted chocolate into the bottom of each muffin liner. Then, add 1 teaspoon of the peanut butter mixture to the center. Top with another teaspoon of melted chocolate, adding a bit more if needed to fully cover the filling.

Place the cups in the freezer until the chocolate is firm. Once set, sprinkle with flaky sea salt and store in the fridge for up to one week.