Preheat oven to 350 degrees with the oven rack in the middle. Line a baking sheet with parchment paper.
In a medium size mixing bowl, whisk to combine the flour, baking powder, baking soda, cardamom, clove, cinnamon, ginger, star anise, white pepper and salt. Set aside.
In a separate medium size mixing bowl, whisk to combine the 2 eggs + 2 egg yolks and sugar until well combined, about 1 minute. Add the vanilla extract and whisk to combine.
Add the dry ingredients to the egg mixture, fold until just combined. Will look dry.
Divide the dough in half. Use your hands to press the dough into 2 separate 9" x 3" loaves. Pat down until they are about 1/2" thick.
Bake for 35 minutes, turning the cookie sheet half way thru baking. Remove and allow the loaves to cool for 10 minutes.
Lower the oven temperature to 325 degrees.
Once the loaves are cool enough to handle, use a serrated knife to cut 1/2" thick slices. Bake the slices another 15 minutes, turning each slice half way thru baking. Remove from the oven and allow to cool completely.