Preheat oven to 325. Line two baking sheets with silicone liners or parchment paper.
In a small bowl, combine ⅓ cup flour, baking powder and salt. Set aside.
In a heatproof bowl set over simmering water, melt the butter, unsweetened chocolate, ½ cup chocolate chips and peanut butter, stirring until melted. Turn off the heat, remove the bowl from the simmering water and set aside to cool for 15 minutes.
In a large bowl, beat eggs, espresso powder, vanilla extract and sugar on medium high for 2 minutes. Reduce speed to low and slowly add the cooled chocolate mixture. Once the chocolate is evenly incorporated, add the flour mixture, stirring by hand until just combined.
In a small bowl, combine the remaining half cup of chocolate chips along with the peanut butter chips, peanuts and 1 tablespoon of flour. Toss several times to evenly incorporate the flour. Fold into the cookie batter.
Using a 1 ½ tablespoon scoop, or two spoons, drop rounded mounds of batter onto the prepared baking sheets. Bake the cookies for 13-15 minutes, until the tops are crackly and the centers of the cookies appear dry. Be careful not to over bake these. Just like brownies, you want the middle to be just barely done. Cool on baking sheets.