Preheat the oven to 400ºF. Grease a 9-inch round baking pan.
In a large bowl, combine the flour, baking powder, salt, and baking soda. Stir in the vegetable oil. Add in the buttermilk and stir just until combined.
Dump the dough onto a floured surface and knead the dough until it is smooth. Roll it into a 15x8-inch rectangle. Spread the butter over the dough.
In a small bowl, combine the brown sugar, cinnamon and cardamom. Sprinkle the mixture over the butter. Roll up the dough like a jelly roll and pinch the seams to seal. Cut into 9 equal slices and arrange in the prepared pan, cut side up.
Bake in the preheated oven until lightly browned, 15 to 20 minutes.
While the biscuits are baking, whisk together the powdered sugar, whipping cream, butter, and salt.
Remove from biscuits from the oven and pour the milk evenly over the top.
Spread the icing on the biscuits and serve warm.
