Preheat your oven to 325 degrees.

Grease a bundt pan with butter or coconut oil. Set aside.

In a bowl whisk together the brown rice flour, potato starch, tapioca flour, baking powder, xanthan gum, baking soda, salt, cinnamon, ginger, cloves, allspice and nutmeg. Set aside.

In the bowl of your mixer blend together the butter, granulated sugar and brown sugar. Add the molasses and eggs. Blend until they are incorporated into the batter. 

Add the pumpkin puree, sour cream and vanilla. Blend until just mixed together. Add the dry ingredients and blend until they are just mixed in.

Pour the cake batter into the bundt pan evenly.

Bake at 325 degrees for 1 hour 5 minutes. The cake will be browned and spring back to your touch.

Let the cake cool for 10 minutes in the pan and then tip onto a serving dish or cooling rack to finish cooling.

I like this cake with my Maple Glaze. You could also use powdered sugar or a simple Vanilla Glaze.