In a bowl, combine the flour, sugar, baking powder, salt, cardamom and chopped almonds.
Add the beaten eggs, melted butter, vanilla and almond extracts, and stir everything together into a soft, sticky dough.
Cover the bowl and chill the dough for 1 1/2 hours.
Preheat the oven to 350 F, and line a large baking sheet (or two medium baking sheets) with parchment baking paper.
Divide the chilled dough into three portions, dusting each portion with a little flour to keep the dough from sticking to your hands. Roll or press each portion of dough out into a rectangular-shaped log, measuring about 3x8 inches and about 3/4 inch thick.Make sure you leave about 4 inches between each portion of dough on the baking sheet, since they will spread out as they bake. Use two baking sheets if you need more space.
Brush the top of the dough with egg white and sprinkle with a few tablespoons of granulated sugar.
Bake the biscotti on the center oven rack for 20 minutes. Remove from the oven, and let cool for exactly 10 minutes on the baking sheet.Reduce the oven temperature to 325 F.
Use a large spatula or cake lifter to carefully lift the slabs of biscotti onto a cutting board. Use a sharp knife (I find that a chef's knife works best) to slice the slabs into individual biscotti about 3/4 - 1 inch thick. Place the biscotti back onto the baking sheet, turned on their side with the cut side facing up.
Bake the biscotti for 10 minutes. Turn the biscotti over, so the other cut side is facing up, and bake for 10 more minutes. Cool completely.
Make sure the biscotti is completely cooled before storing it in an airtight container.