01 - Preheat oven to 350°F. Line a baking sheet with parchment paper.
02 - Whisk together flour, baking powder, and salt in a medium bowl until evenly combined.
03 - Beat softened butter and granulated sugar in a large bowl until light and fluffy, about 2–3 minutes.
04 - Add eggs one at a time, beating thoroughly after each addition. Mix in vanilla and almond extract until incorporated.
05 - Gradually add dry ingredients to wet mixture, mixing until just combined and dough forms.
06 - Divide dough in half. On a lightly floured surface, shape each half into a 12-inch by 2-inch log.
07 - Place logs on prepared baking sheet, spacing apart. Flatten slightly with hands and sprinkle with coarse sugar if desired.
08 - Bake at 350°F for 25–28 minutes until logs are lightly golden and set. Cool for 10 minutes on the pan.
09 - Lower oven temperature to 300°F.
10 - Cut logs diagonally into 3/4-inch slices using a sharp serrated knife. Arrange slices cut side down on baking sheet.
11 - Bake at 300°F for 12–15 minutes, flip biscotti, then bake 10–12 minutes longer until crisp and golden brown.
12 - Cool completely on wire rack. Drizzle with melted white chocolate if desired and let set before serving.