In a medium bowl, whisk together the flour, baking powder, salt, cinnamon, and brown sugar. Add the butter. Using a pastry cutter or a fork, cut the butter into the flour mixture, until the mixture resembles coarse crumbs. (It's sometimes easier to just use your hands and squeeze the butter and flour together utnil it resembles pea-sized crumbs!)

In a separate bowl, whisk together the mashed sweet potato and buttermilk. Add buttermilk mixture to flour mixture and fold together with a rubber spatula until just combined. (Don't be afraid to get in there with your hands too!) Dough will be sticky.

Genrously flour your countertop with flour and turn the dough out onto the countertop. Add 2 tablespoons of flour onto the dough and knead it several times to combine. If dough still seems sticky, add another spoonful of flour or two. Pat dough into a 1'' thick disk. Roughly fold it in half, and then in quarters, and repeat this a few times (this helps to create those biscuit layers!). Form dough again into a 1'' thick, even disk. Using a floured 3-inch biscuit cutter, cut your biscuits, then gather scraps and repeat as necessary until you have 6 biscuits. Place biscuits on a parchment lined baking sheet and chill in the fridge for 15 minutes.

Preheat oven to 425℉. Once biscuits have chilled, brush the tops with melted butter and sprinkle each biscuit top with a few good pinches of flaky salt. Bake for 18-22 minutes, or until biscuits are fluffy and golden brown on the edges. Let cool for a few minutes, then serve warm with salted cranberry maple butter.

In a medium bowl, mix together the softened butter, flaky salt, maple syrup, and cranberry sauce together with a spoon or rubber spatula until combined.