Preheat the oven to 355°F (180°C). Line a baking sheet with parchment. In a large bowl, mix eggs, sugar, citrus zest, salt, and vanilla extract using a fork. Add sifted dry ingredients (flour and baking powder) and mix with the fork, then with your hands. Add whole almonds and knead well.

Transfer the dough to a lightly floured work surface and divide it into two equal parts. You may add little extra flour if the dough sticks to your hands, but avoid adding too much flour. Shape two dough logs by using your hands to roll them on a flat surface. Then, gently flatten the logs until they are approximately 1.5 inches (4 cm) wide. Transfer the logs to the prepared baking sheet. Space two biscotti logs apart on a baking tray, as they tend to spread during the baking.

Bake the logs in the middle rack of the oven for 18-20 minutes. Remove them from the oven, let them cool for 5 minutes, and transfer to a cutting board. Cut the hot logs into 1/2-inch (1-1.5 cm) thick slices with a serrated knife slightly diagonally. Place the slices cut-side up on the baking sheet with parchment in a single layer.

Bake them for 4 minutes on one side, then turn the cookies over and bake for another 4 minutes. Finally, remove the cantucci from the oven and let them cool on a wire rack.