Preheat the oven to 350°F. Line a sheet pan with parchment paper.

In a small bowl, whisk together the flour, baking powder, salt, cinnamon, ginger, allspice, cardamom, and nutmeg.

In a large mixing bowl, beat the butter, white sugar, and brown sugar together until light and fluffy, 2-3 minutes. Add the molasses and vanilla extract. Then, add the eggs one at a time, mixing until thoroughly combined. Add the flour mixture until you have a stiff, but sticky, dough.

Using damp or floured hands, divide the dough into two equally-sized balls. Place the balls of dough next to each other on the parchment-lined sheet pan. Then, working one at a time, shape each ball into a smooth rectangular log that is approximately 7x4x1'', leaving a couple of inches of space around the logs. Continue wetting or flouring your hands as needed. The logs should be parallel on the sheet pan.

Place the sheet pan on top of another sheet pan so that you have a double pan (this will prevent the bottom of the cookies from burning). **Bake for 20-25 minutes, rotating halfway through until the top of the logs are dry and the edges are just starting to turn golden-brown. Remove from the oven and allow to cool for 10 minutes.

Lower the oven to 300°F. Meanwhile, slice the biscotti at a diagonal into 3/4'' cookies using a sharp serrated knife. Discard the very ends or save them for a snack!

Place the sliced biscotti cut-side up on the parchment-lined sheet pan. Bake for 8-10 minutes until the tops are dry, but not burnt. Flip the biscotti, and bake for another 8-10 minutes, until the tops are dry and crisp.

Let the cookies cool on a rack. They will crisp up more as they cool.

In a microwave-safe bowl, microwave the white chocolate in 15-30 second increments, stirring in-between, until it's just melted. Place a piece of parchment paper under the cooling rack topped with the biscotti to prevent a big mess!

Using a piping bag or the tines of a fork, drizzle the white chocolate over the tops of the cookies. Immediately sprinkle with lemon zest and coarse sugar. Let the white chocolate harden, 15-20 minutes.

Enjoy the biscotti with hot coffee, tea, or brandy!