Preheat the oven to 329º F (165° C). Place the almonds on a baking sheet and bake for 10 minutes just until lightly browned.
In a medium bowl sift the flour with the baking powder and salt.
In a large bowl with an electric mixer or hand whisk, cream together the butter and sugar for 3 minutes until the mixture is light and fluffy.
Add in the eggs, vanilla extract, almond extract, orange/lemon zest and beat for 1 minute more until blended.
Add the flour mixture and the almonds and mix with a rubber spatula until a soft dough forms that does not stick to your hands.
Divide the dough into 3 pieces and, on a lightly floured surface, form each piece of dough into a log approximately 9,9 inches (25 cm) long by 2 inches (5 cm) wide.
Place the logs on a large baking sheet lined with baking paper, with about 2 inches (5 cm) apart from each other. Bake at 329º F (165° C) in the center of the oven until lightly browned, about 30 minutes.
After 30 minutes, place the biscotti on a cutting board and let them cool slightly. Using a bread knife, cut the biscotti diagonally into 1-1.5 cm thick pieces.
Place the biscotti back on the baking sheet and bake for another 15 minutes until slightly browned, turning them over halfway through. Transfer the biscotti to a cooling rack and then store them in an airtight container.