Line a muffin tin with parchment paper muffin liners.
Add the chocolate chips and coconut oil to a microwave safe bowl. Microwave the chocolate chips in 30 second intervals, stirring each time, until melted and smooth.
Once the chocolate is melted, stir in the vanilla extract.
Pour 1 heaping teaspoon of the melted chocolate into the bottom of the muffin liner, then spread it out to the edges until it is in a flat layer. Repeat this for all 12 muffin cups.
Place the muffin tin in the refrigerator while you make the peanut butter filling.
Place the peanut butter in a microwave safe bowl and microwave for 15-20 seconds, until it is runny.
Stir in the vanilla protein powder, salt, and maple syrup until combined.
Divide the peanut butter filling into 12 discs that are slightly smaller than the width of the muffin liner.
Remove the muffin tin from the refrigerator and place the peanut butter discs onto the top of each chocolate cup.
If your leftover melted chocolate has hardened, microwave it for another 15-20 seconds to loosen it up.
Drizzle the remaining chocolate over the tops of the peanut butter, smoothing the chocolate out over the top in an even layer to the edges.
Place the peanut butter cups back into the refrigerator for one hour, or until set.
Store leftover peanut butter cups in an airtight container in the refrigerator or freezer.