Ingredients:

  • Unsalted butter, melted — 6 tbsp (85 g)
  • Bittersweet or dark chocolate (60–70% cacao), chopped — 4 oz (113 g)
  • Granulated sugar — 3/4 cup (150 g)
  • Large eggs — 3 (about 150 g total without shells)
  • Pure vanilla extract — 1 tsp (5 ml)
  • PB2 powdered peanut butter (dry powder) — 1/2 cup (48 g)
  • Unsweetened cocoa powder — 1/2 cup (50 g), sifted
  • Fine sea salt — 1/4 tsp (1.5 g)
  • Instant espresso powder (optional) — 1/2 tsp (1 g)
  • Baking powder (optional) — 1/4 tsp (1 g)
  • Optional: Dark chocolate chips or chopped chocolate — 1/2 cup (85 g)
  • Optional: Flaky sea salt for sprinkling
  • Optional: Rehydrated PB2 or natural peanut butter for swirls — 2 tbsp (30 g)

Instructions:

  1. Preheat oven to 350°F (175°C). Line an 8x8 or 9x9-inch (20x20 or 23x23 cm) pan with parchment paper leaving an overhang; lightly grease the parchment.
  2. Gently melt the unsalted butter and chopped dark chocolate together over low heat in a double boiler or in 20–30 second microwave bursts, stirring until smooth. Remove from heat and let cool slightly until warm but not hot.
  3. Whisk the granulated sugar into the warm chocolate-butter mixture until combined. Whisk in the eggs one at a time until the mixture is glossy, then stir in the vanilla. Ensure the mixture has cooled enough so the eggs do not cook.
  4. In a separate bowl, whisk together PB2 powdered peanut butter, sifted cocoa powder, fine sea salt, instant espresso powder (if using), and baking powder (if using) until evenly combined.
  5. Fold the dry ingredients into the chocolate-egg mixture until just combined; avoid overmixing. Fold in dark chocolate chips or chopped chocolate if using, or swirl in rehydrated PB2/peanut butter for a peanut swirl.
  6. Spread the batter evenly in the prepared pan and smooth the top. Bake at 350°F (175°C) for 20–25 minutes for fudgy brownies: edges should be set and slightly pulling from the pan while the center remains slightly wobbly.
  7. Test for doneness with a toothpick: it should come out with moist crumbs, not wet batter. Do not overbake to preserve fudginess.
  8. Cool the brownies in the pan on a rack for 20–30 minutes, then refrigerate for 20–30 minutes if you desire cleaner slices and a firmer texture. Use the parchment overhang to lift brownies from the pan and cut into 12 squares. Sprinkle flaky sea salt if desired.