Preheat oven to 350. Beat eggs and add sugar to blend. Add salt. Sift flour and baking powder and add all at once to eggs. Stir just to blend. Add flavoring or garnish. Spoon mixture lengthwise onto cookie sheet lined with parchment paper or greased. Spoon into a "log", shape as wide as you choose, the width of the "log" will determine the length of the cut biscotti. Make as many "logs" as you have mix. Allow logs to sit for about 10 minutes at room temperature before baking. Bake at 350 for approximately 20 minutes or until center of log springs back when touched. Remove from oven and let cool thoroughly. Cut logs into strips crosswise. Standard is about 1/2 inch. Place each biscotti cut side down onto cookie sheet lined with parchment or lightly greased. Bake again for approximately 15 minutes or until lightly browned on edges. Cool thoroughly, then store in airtight container;
For Hazelnut: 2 cups roughly chopped, sliced, or whole hazelnuts .
For Lemon/Poppy: grated rind of three lemons, 1 teaspoon poppy seeds .
For Ginger: 1 1/2 cups chopped crystallized (candied) ginger.