Preheat your oven to 325 degrees F. Grease a 12-cup bundt pan with Pam's Baking Spray and set it aside.
In a small bowl, mix together ½ cup packed light brown sugar and 1 tablespoon of ground cinnamon. Set this cinnamon swirl mixture aside.
In a medium-sized bowl, combine the flour, baking powder, cardamom, ground cinnamon, pumpkin pie spice ginger, nutmeg, and salt. Set aside.
In a stand mixer fitted with the paddle attachment, cream the granulated sugar, brown and eggs on medium speed until they are light and fluffy, about 4 minutes.
Add the vegetable oil and vanilla extract, and beat on medium speed until fully incorporated, about 30 seconds. Then add the pumpkin puree and mix until combined, about 30 seconds.
With the mixer on the lowest speed, gradually add the dry ingredients to the pumpkin/egg mixture.
Pour half of the pumpkin batter into the prepared bundt pan. Sprinkle the cinnamon sugar mixture evenly on top. Pour the rest of the pumpkin batter on top of the cinnamon sugar.
Bake for 50-55 minutes (or until a toothpick inserted in the center comes out with only a few moist crumbs). Mine took the whole 55 but my oven runs warmer.
Allow the bundt cake to cool for 20 minutes before transferring it to a cake plate or board. While the cake is still slightly warm, use a pastry brush to lightly brush on the melted butter, and then add Turbinado sugar to the top and sides.
Let the cake cool to room temperature and then serve!