Preheat oven to 350°F (175°C). Spread almonds on a baking sheet and toast for 8-10 minutes. Let cool. Chop half of them and leave the rest whole.

In a medium bowl, whisk together the all-purpose flour, baking powder, and salt. Set aside.

In a large bowl using an electric mixer, beat the softened butter and sugar until combined. Add the eggs one at a time, beating well after each addition. Stir in the vanilla and almond extracts.

Gradually add the dry flour mixture to the wet ingredients, mixing on low speed until just combined. The dough will be slightly sticky. Gently fold in the toasted almonds.

Line a large baking sheet with parchment paper. Divide the dough in half. Using lightly floured hands, shape each half into a log about 10 inches long and 2.5 inches wide, spacing them well apart.

Bake the logs at 350°F (175°C) for 25-30 minutes until golden brown and firm to the touch. Remove from the oven and let cool on the pan for exactly 15 minutes. Reduce the oven temperature to 325°F (165°C).

Carefully transfer the slightly cooled logs to a cutting board. Using a sharp serrated knife, use a gentle sawing motion to cut the logs diagonally into 3/4-inch thick slices.

Place the slices cut-side down back onto the parchment-lined baking sheet. Bake at 325°F (165°C) for 10-12 minutes. Flip each slice over and bake for another 10-12 minutes until dry and crisp.

Transfer the biscotti to a wire rack to cool completely. They will harden further as they cool.