Preheat oven to 325°. Grease 1 baking sheet.
Place the almonds on a baking sheet and bake for 8 to 10 minutes, until lightly browned. Remove, let cool, and chop coarsely.
Combine the flour, baking powder, salt, and sugar in a large bowl. Stir in the toasted almonds.
In a small bowl, lightly beat the eggs with the vanilla and almond extract. Add to the dry ingredients and blend thoroughly to form a sticky dough. Cut the dough in half. Flour your hands and shape each dough into a log about 14 inches long. Place the logs on the prepared baking sheet and bake for 30 minutes or until a toothpick inserted in the center comes out clean. Let cool for 10 minutes.
Cut the logs diagonally into slices about ½ inch thick. Place cut-side down on 2 ungreased baking sheets. Bake for a total of 15 minutes, removing the baking sheets from the oven at the halfway point and turning the cookies over. Return to the oven, moving the baking sheet that was on the top rack to the bottom rack and vice versa (this ensures the cookies cook evenly). Finish baking. Let cool.
Break the chocolate into pieces. Melt the shortening and chocolate in a metal bowl placed on top of a heavy pot filled halfway with barely simmering water (or use the top of a double boiler if you have one). Melt over low heat, stirring regularly and making sure the chocolate doesn't burn. Use the back of a metal spatula or wooden spoon to spread the melted chocolate over half of one side of each biscotti. Let dry. Store the biscotti in a cookie tin or other airtight container.
Yields about 40 cookies
Light and crisp biscotti are the perfect cookies for dunking into tea or coffee.