In a food processor, combine flour, baking powder, sugar, cardamom, cinnamon, salt, and orange zest. Pulse a couple times to mix, then cut the butter into chunks and add to the food processor. Process until butter is completely incorporated, and the mixture resembles the texture of slightly damp sand. Transfer to a large bowl.
In another bowl, combine heavy cream, egg, and vanilla, and whisk to combine. Pour this mixture over the flour mixture and fold until a dough forms.
Preheat your oven to 350 degrees and line two baking sheets with parchment paper or a silpat baking mat. Lightly dust a clean surface with flour. Divide the scone dough in half, and form each half into flat round disks about half an inch thick. (You may need to use flour on your hands.) Slice each round of dough into 8 wedges, giving you a grand total of 16 wedges.
Carefully transfer the wedges to the prepared baking sheets, placing 8 on each. Space the wedges at least 2-3 inches apart because they will puff up in the oven.
Bake for 15 minutes. The scones should be golden brown and crisp on the outside. Let the scones cool before glazing.