Preheat your oven to 350°F (175°C).
Grease your 8x8 inch baking pan or line it with parchment paper.
In a mixing bowl, combine the melted unsalted butter, light brown sugar, and creamy peanut butter. Whisk until smooth.
Add the large eggs, one at a time, followed by the vanilla extract. Whisk until incorporated.
In a separate bowl, whisk together the flour, baking powder, baking soda, and salt. Gradually add to the wet mixture, stirring until just combined.
Gently fold in the unwrapped Rolo candies until evenly distributed.
Pour the batter into the prepared pan and bake for 25-30 minutes or until a toothpick comes out clean.
Allow to cool for 10 minutes before transferring to a wire rack to cool completely. Cut into squares and enjoy!