Grease a muffin tin with cooking spray and line with cupcake liners.
Mix Peanut Butter with granulated sugar and keep aside.
Fill each cup with one layer of melted dark chocolate about (2-Tbsp), followed by another layer of peanut butter (1-Tbsp) and lastly another layer of melted dark chocolate. Spread the chocolate evenly.
Finally, place them in the freezer for 2 hours. Remove the liners carefully. And, your Peanut Butter cups are ready.