Ingredients:

  • 1 can sweetened condensed milk, 14 oz (396 g)
  • 1 cup creamy peanut butter (256 g)
  • 2 cups confectioners' sugar, sifted (240 g)
  • 1 tsp vanilla extract (5 ml)
  • 1 tsp butter, for greasing (5 g)
  • ¼ tsp flaky sea salt, optional, for topping (1.5 g)

Instructions:

  1. Grease the 8-inch square pan lightly with the butter. Line it with parchment paper, leaving an overhang on two sides.
  2. Press the confectioners' sugar through a fine-mesh sieve into a bowl until no lumps remain.
  3. Combine the condensed milk and peanut butter in a large microwave-safe bowl. Microwave for 60 seconds, then stir until smooth. Continue heating in 20-second bursts, stirring between each, until warm and glossy. Stop heating as soon as it steams. Do not let it bubble.
  4. Stir in the vanilla extract until fully combined.
  5. Add half the sifted sugar and stir until mostly combined. Add the remaining sugar and stir until no white streaks remain. The fudge should be thick, glossy, and pull away from the sides of the bowl. If too stiff to stir, microwave for 10 seconds and continue stirring.
  6. Scrape the fudge into the prepared pan and smooth the top with an offset spatula or the back of a spoon. Sprinkle with flaky sea salt, if using, and press it in lightly.
  7. Cover and refrigerate for 2 hours, until the surface feels dry and no longer tacky when touched.
  8. Lift the fudge out of the pan using the parchment overhang. Run a sharp knife under hot water, wipe it dry, and cut a 5 by 5 grid into 25 squares. Wipe the blade between cuts.