01 -
Combine granulated sugar, brown sugar, butter, and milk in a saucepan. Heat over medium heat, stirring constantly until the mixture reaches 236°F (soft-ball stage), then immediately remove from heat.
02 -
Add peanut butter and mini marshmallows to the hot mixture. Beat vigorously until the mixture thickens and begins to lose its gloss, indicating it is setting.
03 -
Transfer the mixture into a buttered 8x8-inch baking pan or one lined with parchment paper for easy removal. Spread evenly.
04 -
Allow the fudge to cool to room temperature and harden, which takes approximately 1 to 2 hours. Once firm, cut into 16 equal squares for serving.