Begin by preheating your oven to 325°F (163°C) and position the rack in the center for even baking. Spread the whole almonds out on a baking sheet in a single layer and toast them in the oven for 12 to 15 minutes, or until fragrant and lightly golden. Once done, remove from the oven and set aside to cool before chopping coarsely.
In the meantime, combine the flour, baking powder, salt, granulated sugar, and brown sugar in a medium mixing bowl. Whisk until well blended and no lumps remain.
In a separate large bowl, lightly beat the eggs. Add the olive oil, black cherry balsamic, vanilla extract, and lemon zest. Whisk until the mixture is smooth and cohesive.
Once the almonds have cooled, chop them into large, rough pieces.
Prepare a baking sheet with parchment paper. Gradually add the dry ingredients into the egg mixture, stirring gently with a wooden spoon until just combined. Avoid overmixing to preserve the dough’s texture.
Fold the chopped almonds into the dough, followed by the dried cherries if using. Use a large spoon or scoop to transfer portions of dough onto the prepared baking sheet, shaping two long, even logs side by side. With damp hands, gently press and shape each into a smooth log about 2 inches wide.
Bake the logs for about 30 minutes, or until they are lightly golden and feel firm to the touch. Let them cool on the pan for 10 minutes, allowing the structure to set slightly before slicing.
Transfer the partially cooled logs to a cutting board. Using a serrated knife, slice them on the diagonal into ½ to ¾-inch thick pieces. Lay the slices cut-side down on the baking sheet.
Return them to the oven and bake for an additional 15 to 20 minutes, flipping each piece halfway through to ensure even crisping. The longer they bake, the crunchier the texture becomes.
Once done, transfer the biscotti to a wire rack and let them cool completely. They’ll crisp up further as they cool, creating the signature bite that makes biscotti so satisfying.