Line a 12-cup mini muffin pan or cupcake pan with paper liners.
In a medium saucepan, combine melted coconut oil, cocoa powder, maple syrup, and salt.
Warm over medium heat while whisking until smooth and fully combined. Alternatively, use a microwave-safe bowl and heat in short intervals.
Spoon approximately 1 tablespoon of chocolate mixture into each liner.
Tilt and spread the chocolate mixture up the sides of each liner to create a thin chocolate shell.
Place the pan in the refrigerator for 10–15 minutes until the chocolate hardens completely.
While the shells chill, prepare the filling by combining peanut butter (or almond butter) and maple syrup in a small bowl. Stir until smooth.
Remove the chilled chocolate shells from the refrigerator.
Divide the nut butter mixture evenly among the cups.
Spoon the remaining chocolate mixture over the filling, ensuring the filling is completely covered.
If the chocolate mixture thickens or hardens, gently reheat it before using.
Return the cups to the refrigerator and chill for about 20 minutes, or until fully set.
Once firm, carefully peel away the liners and enjoy your Healthy Homemade Peanut Butter Cups.