Heat the chocolate chips and coconut oil (or butter) in a bowl in the microwave for 20 second intervals, stirring well in between each interval, until the chocolate is completely melted and the mixture is creamy (about 50 to 60 seconds total).

Line a muffin tray with 8 muffin liners. Pour a thin layer of the chocolate mixture into each of the muffin papers to create the bottom layer of chocolate, then immediately transfer to the freezer and freeze for 15 minutes (or until the chocolate has completely set up.

While the chocolate is setting up, prepare the peanut butter filling. Add the peanut butter, protein powder, sugar-free confectioner’s sugar, vanilla extract, and sea salt to a food processor. Process until everything is very well combined. 

Roll the peanut butter mixture into 8 even-sized balls then press each ball into each muffin paper in the cupcake tin, creating the peanut butter center. Drizzle the rest of the melted chocolate evenly over the peanut butter layer. If desired, sprinkle the wet chocolate with flaky sea salt for that sweet and salty effect.

Freeze the peanut butter cups for at least 15 minutes, or until the chocolate has completely set up.

Peel the muffin papers off and enjoy!