Preheat your oven to 350 degrees F (175 C). Butter or line a 9x13-inch pan with parchment paper. Set aside.
In a medium bowl, whisk together the flour, cinnamon, allspice, Chai tea leaves, ground ginger and baking soda.
In the bowl of a stand mixer cream the butter and sugar together until soft. Add the eggs one at a time, beating well after each addition. Add the vanilla and fresh ginger and mix. With the mixer on low speed, slowly add the flour mixture and mix until combined.
Spread the batter into the pan, making sure it is evenly distributed. Make sure to smooth out the top of the batter (I like to use an offset spatula). Sprinkle the top of the bars with extra sugar, if desired.
Slide the pan into the oven and bake for about 25 minutes, or until a toothpick comes out nearly clean. Serve warm or cold, plain or with whipped cream.
adapted from Nika