1) Sift the flour and baking powder to make sure it is really fluffy.
2) In a second, larger bowl, combine sugar, eggs, melted butter, vanilla, booze, and orange zest together. Stir in the flour mixture 1/3 at a time until you end up with dough that resembles cookie dough.
3) After the dough is formed, gently fold in the almonds.
4) Line a sheet pan with parchment paper. Take out about half of the dough and form it into a loaf that should be about 13 inches long and 3 inches wide. Repeat so you have two loaves.
5) Beat the egg white until it has medium peaks and brush each loaf with the frothy mixture.
6) Bake at 350 degrees for about 30 minutes or until they are golden brown.
7) Cool completely on a wire rack. Make sure they are cool before continuing – approximately 30 minutes. Keep the oven hot at 350 degrees.
8) Once each loaf is cooled, slice it on a diagonal with a good, sharp bread knife or serrated knife. Take the time to try to make sure that the slices are pretty even and uniform.
9) Get rid of the parchment paper and lay each slice down on the baking sheet.
10) Bake at 350 for 12 minutes and then turn and bake for another 8-10 minutes until they are a light, golden brown color.
11) Again, cool them on a wire rack.
12) Optionally, dip biscotti in chocolate. Store the regular biscotti in a sealed plastic bag once they are entirely cool. Store the chocolate ones in the fridge.