Whisk the flour, sugar, baking powder, cinnamon, and salt together in a large bowl. Grate the frozen butter using a box grater. Add it to the flour mixture and combine with a pastry cutter.
Place in the refrigerator
Preheat the oven to 400°F
Line a large baking tray with parchment paper
Stir the wet ingredients( the cream, the egg, and the vanilla extract) minus the blueberries together in a small bowl. Drizzle all over the dry ingredients
Add the blueberries, fold together gently until everything appears moistened. Do not over mix
Flour your workspace and hands
Pour the dough onto your workspace, form the dough into a round ball as best you can. This is a sticky moist dough,
Press into the dough ball gently starting at the middle until you have an even circle about 8 inches in diameter
Then using a pizza cutter or a sharp knife cut like you would a pizza into 8 slices
Use a spatula to lay them onto the parchment paper-lined baking sheet and place them into the oven on the top or middle rack.
Check on them in 20 minutes but likely they will be done closer to 25. You will know they are done when they are golden brown on the tops.
Remove them to a baking rack to cool