Jersey Black Butter and Hazelnut Biscotti

Preheat oven to 350°F (175°C). Line a baking sheet with parchment paper.

In a medium bowl, whisk together flour, baking powder, and salt.

In a separate large bowl, cream together the softened Jersey butter and granulated sugar until light and fluffy.

Beat in the Jersey Black Butter until well combined.

Beat in the eggs one at a time, then stir in the vanilla extract and the mashed Jersey Royal potato.

Gradually add the dry ingredients to the wet ingredients, mixing until just combined. Do not overmix.

Fold in the toasted hazelnuts.

Divide the dough in half. On a lightly floured surface, shape each half into a log about 12 inches long and 2 inches wide. Place the logs on the prepared baking sheet.

Bake for 30 minutes, or until golden brown.

Remove from the oven and let cool on the baking sheet for 10 minutes.

Reduce oven temperature to 300°F (150°C).

Using a serrated knife, slice each log diagonally into 1/2-inch thick slices.

Arrange the biscotti slices, cut-side up, on the baking sheet.

Bake for 10 minutes on each side, or until golden brown and crisp.

Let the biscotti cool completely on a wire rack before storing in an airtight container.