Step 1

Heat the oven to 350°F with a rack in the middle position. Line a rimmed baking sheet with kitchen parchment. In a small bowl, whisk together the flour, baking powder and salt. In a large bowl, combine the sugar and both zests. Using your fingers, rub the zest into the sugar until fragrant. Add the honey and eggs, then beat with a hand mixer on medium until slightly thickened and almost doubled in volume, about 1 minute (alternative, whisk vigorously by hand for about 2 minutes).

Step 2

Add the flour mixture and, using a silicone spatula, stir and fold, mashing the mixture against the bowl, until the dry ingredients are evenly moistened. Add the almonds; lightly flour your hands and knead gently until they are evenly distributed.

Step 3

Lightly flour the counter, then turn the dough out onto it and divide in half. Moisten your hands with water and roll one portion into a log 14 inches long and 2 inches wide. Place the log on one side of the prepared baking sheet. Shape the remaining dough in the same way and place on the other side of the baking sheet, spacing the logs about 4 inches apart.

Step 4

Bake until the logs are deep golden brown and have spread into flat, fissured loaves that are firm on the surface and appear dry in the cracks, about 30 minutes, rotating the baking sheet halfway through. Cool on the baking sheet on a wire rack for 20 minutes; immediately after removing from the oven, reduce the temperature to 275°F.

Step 5

Using a wide metal spatula, carefully transfer the loaves to a cutting board; reserve the baking sheet and its parchment. Using a serrated knife and a gentle sawing motion, cut each still-warm loaf on the diagonal into ½-inch-thick slices.

Step 6

Place the biscotti cut side up in a single layer on the reserved baking sheet. Bake until firm and dry, 30 to 35 minutes, rotating the baking sheet about halfway through. Cool on the baking sheet on a wire rack for about 10 minutes. Transfer the biscotti directly to the rack and cool completely.