Add flour and starches to large bowl; whisk to combine.
Place 2 cups of the flour blend in the bowl of a stand mixer. Add the xanthan gum and cardamom. Turn mixer on low to combine. Set remaining flour aside (to be added in step 6).
Place warm water, yeast, and 1/4 teaspoon sugar together in a small bowl. Stir until yeast is dissolved. Set aside for 5-10 minutes, or until yeast is foamy.
In a small saucepan or microwave-safe dish, heat the milk, butter, 1/4 cup sugar, and salt. Stir until sugar is dissolved; do not let it boil. It should just be pretty hot.
In a medium bowl, whisk eggs together with vanilla and orange zest. Carefully add the milk mixture in a slow, steady stream to the eggs and whisk well. Be sure to add the milk slowly so it doesn’t curdle the eggs. Let stand until still lukewarm, about 100°F
Fit mixer with paddle attachment. With mixer on low speed, and add the milk and egg mixture in a slow steady stream to the flour mixture. Let mix, raising the speed to medium, until smooth. Add yeast mixture. Lower the speed and add about 2 – 2 1/2 cups more of the gluten-free flour blend. The dough should be fairly sticky and smooth, but not too stiff. Turn off mixer and let dough stand for a few minutes.
Grease a bundt pan. Transfer the dough to the pan and smooth it evenly. Brush the top with the melted butter or oil. Cover with plastic wrap and let rise for 45-60 minutes in a warm place. The dough won’t have doubled, but it will have risen quite a bit.
Preheat oven to 400°F.
Bake for 40-45 minutes, or until golden and baked through. Let cool in the pan for a few minutes, then turn out onto a rack to finish cooling.
Make the glaze: whisk orange juice and powdered sugar together. Pour over the cake and let stand for a few minutes before cutting and serving.