Preheat the oven to 325°F. Line a baking sheet with parchment paper.
Spread the nuts on a second baking sheet and roast for 12-15 minutes, until fragrant and lightly golden. Allow nuts to cool for 10-20 minutes on the pan. Then finely chop 1/4 cup and coarsely chop the remainder.
In a large mixing bowl, blend the butter and sugar together just until combined and slightly creamy—do not overmix, as cold butter is key to a crisp texture.
Beat in the egg until incorporated, then stir in the anisette liqueur to combine.
In a separate bowl, whisk together the flour, cornmeal, baking powder, salt, anise seeds, and chopped nuts. Fold these dry ingredients gradually into the butter mixture using a rubber spatula. Mix until a stiff, unified dough forms.
Lightly flour your hands and work surface. Divide the dough in half and roll each into a log about 12 inches long and 2 inches wide. Gently flatten tops for even baking.
Arrange the logs spaced apart on the prepared baking sheet. Bake for 15–20 minutes, rotating pan halfway through, until the logs are firm, lightly golden, and feel dry to the touch at the center—do not underbake.
Remove logs from oven and cool for 10-15 minutes on the pan. The logs should still be slightly warm but firm.
Carefully slice the logs on the diagonal into 3/4- to 1-inch slices using a serrated knife.
Arrange the slices cut-side down on the baking sheet. Bake for 8-12 minutes, flipping halfway, until dry and golden. If you want extra crispness, bake a few extra minutes.
Remove from oven and transfer the biscotti to a wire rack to cool completely, about 30-60 minutes.
Serve immediately or store in an airtight container.