Place all-purpose flour in the bowl of a stand mixer fitted with the paddle attachment.
Sift cake flour, baking powder, baking soda, and sugar over the flour.
Place bowl on stand and mix on low for about 30 seconds.
Turn off mixer, add butter, and pulse to start combining. Mix on low until no large pieces of butter remain, about 3 minutes.
With the mixer on low, slowly add heavy cream and créme fraîche and mix until a dough forms and sticks to the paddle.
Turn out dough onto a clean work surface.
Cut cinnamon honey block into 1/4-inch cubes and distribute over the scone dough. Use the heel of your hand to smear the dough and cubes together, folding and turning over about 5 times.
Transfer dough to a large piece of plastic wrap and cover with another piece of plastic wrap. Shape into a block about 7 1/2x10 inches. Wrap tightly and refrigerate for at least 2 hours.
Remove dough and cut into 5 long strips, each about 1 1/2 inches wide. Cut each strip into 4 blocks about 2 1/2 inches long. Transfer to a baking sheet lined with parchment or silicone baking mat. Freeze at least 4 hours, preferably overnight. Once frozen, the scones can be transferred to an airtight container and kept frozen for a month,
Preheat oven to 350°F. Arrange scones on parchment-lined baking, leaving about an inch of space between them.
Bake 30 minutes, rotating sheets from top to bottom and front to back halfway through, or until golden brown.