Preheat oven to 325°F/160°C. Line a baking sheet with parchment paper and set aside.

In a large bowl, sift together flour, baking powder, and salt. Set aside.

In a mixer bowl fitted with the whisk attachment, whisk eggs on high speed until light and pale in color, about 2 minutes. On low speed, slowly add sugar, followed by butter, vanilla, and lastly the peanut butter. Continue mixing just until all ingredients are combined. On low speed, add the flour mixture in 2 additions and mix just until combined. Fold in peanuts and chocolate.

On a lightly floured surface, form dough into a ball. It will be easier if your hands are slightly wet. Divide into 2 equal pieces. Shape each half into a long rectangle around 14x2.5 inch/35x6 cm in size and place them on the baking sheet, spacing them at least 4 inch/10cm from each other. Bake for about 25 minutes, until slightly risen, firm to the touch, brown around the edges, and the top begins to crack. Cool on a wire rack for 30 minutes. Cut logs into slices, around ½-inch thick/1.5 cm (I cut each log into 20 pieces), using a serrated knife. Return slices cut-side up to the pan in a single layer. Place pan in the oven and bake for 10 minutes until crisp and golden brown, then flip slices over and bake for another 10 minutes (the longer they stay in the oven, the harder they become). Allow cookies to cool completely on a wire rack.

Store cookies in an airtight container at room temperature for up to a month.