Gather the dough together and divide in half. Put each half on either side of the baking sheet with lots of room between one another. Shape each half of the dough into a flatten rectangle that is about 0.5” thick.
Bake for 30 minutes, until slightly golden.
Remove the biscotti from the oven. Let stand for 10 minutes. Continue to keep the oven on during this time.
Once the biscotti is cool enough to handle, move it to a cutting board. Cut the biscotti in 0.5” thick pieces. Lay each piece on a wire cooling rack with the cut side facing down.
Put the biscotti on the cooling rack back into the oven for 20-30 minutes. They should feel firm when they are down. They will harden up more then they cool.
While the biscotti finish baking, beat the egg white and lemon juice until you reach soft peeks. Beat in icing sugar until smooth and it becomes thick like gooey marshmallows.