Preheat oven to 350°F.
Beat butter and sugar in large bowl.
Add eggs, one at a time, blending until combined.
Add vanilla extract, mixing until smooth.
Add flour, peanut butter powder, baking powder, and salt, mixing until combined.
Stir peanuts and chocolate chips into dough.
Divide dough in half.
Shape each half into a 10″ x 3″ rectangle, using floured hands.
Set each loaf 2″ apart on a parchment-paper lined baking sheet.
Bake for 28 minutes or until the dough is set.
Leaving the oven on, remove the biscotti loaves and cool for 15 minutes on the baking sheet.
Using a butcher knife, cut the loaves into diagonal slices, 3/4″ thick.
Place slices on cookie sheet with the cut sides down. Bake for 8 to 9 minutes.
Turn over slices, and bake for 8 to 9 minutes more.
Remove biscotti from oven, and allow to cool completely on a cooling rack.
Store in a sealed container for up to a month.
