Gather your ingredients.
Line a mini muffin pan with mini paper muffin tins.
Melt butter in a small saucepan over medium heat.
Add brown sugar and stir to combine.
Add peanut butter and mix thoroughly until mixture starts to gently bubble.
Remove the mixture from heat and add the powdered sugar. Add ¼ cup at a time, making sure to stir constantly to dissolve the powdered sugar into the mixture. Set pb mixture aside to cool.
Melt half the chocolate in the microwave, microwaving for 30 seconds at a time and stirring in between.
Pour about 1½ tsp of melted chocolate into each muffin cup.
Scoop up one teaspoon of the peanut butter filling and roll into a ball. Then flatten it slightly and place in the center of the muffin cup. Repeat with all peanut butter cups.
Refrigerate for 20 minutes until the chocolate is set.
Melt the remaining chocolate in the microwave. Pour about 1½ tsp of melted chocolate into each cup, covering the peanut butter filling. Then, gently bang the tin on your counter to even out the tops.
Refrigerate the cups for 20 minutes until the chocolate is set and then remove the muffin tins and serve.
This recipe is inspired by: http://www.recipetineats.com/homemade-reeses-peanut-butter-cups/