Sift together flours, baking powder, baking soda, and sugar into the bowl of a stand mixer. Add salt.
Using the paddle attachment for the mixer, mix on low for 15 seconds to distribute the salt.
Add the butter and mix on low until the butter is completely incorporated and the mixture looks like coarse cornmeal, about 3 minutes.
Add the heavy cream and créme fraîche and mix until all the ingredients are moistened.
Add the cheese and rosemary and pulse to incorporate.
Turn the mixture out unto a clean work surface, and, using the heel of your hand and a dough scraper, shape into a 7x9 inch block.
Wrap in plastic and refrigerate 2 hours.
Cut block in half lengthwise, then cut each section into 7 scones. Place on a baking sheet lined with a silicone baking mat. Cover with plastic wrap and freeze overnight. Scones may be transferred to a plastic bag and kept frozen for longer term storage.
Preheat oven to 350°F.
Arrange scones about an inch apart on baking sheets lined with silicone mats. Brush with heavy cream, and sprinkle with black pepper and cheese.
Bake for 33 to 36 minutes, rotating from top to bottom and front to back halfway through, or until puffed and browned. Serve warm.