Preheat oven to 350°. Line baking sheet with parchment paper. Beat the eggs, sugar, baking powder, salt, and vanilla until light and thick. Lower mixer speed and add flour to combine. Add optional nuts or chips. Use a plastic dough scraper to remove the dough and form into a log on the parchment paper about 14” long and 2 ½” wide. Use wet hands or a wet dough scraper to smooth the top. Bake 25 min, remove from oven and cool 15 min. Using a spray bottle, lightly mist the light with water 5 minutes before cutting. This will make slicing easier. Cut the log on the diagonal into about ½” slices. Set the biscotti upright back on the prepared baking sheet and bake for 25 minutes. Cool on wire rack.