01 - Preheat the oven to 220°C. Line a baking sheet with parchment paper.
02 - In a large bowl, whisk together the flour, granulated sugar, baking powder, baking soda, and salt until evenly mixed.
03 - Add the cold cubed butter to the dry mixture. Using a pastry cutter or your fingertips, work the butter into the flour until the mixture resembles coarse crumbs.
04 - In a separate bowl, whisk together the mashed sweet potatoes and buttermilk until smooth.
05 - Add the sweet potato mixture to the dry ingredients. Gently stir just until the dough comes together. Avoid overmixing.
06 - Transfer the dough to a lightly floured surface. Pat or roll the dough to approximately 2.5 cm thickness.
07 - Using a 6 cm biscuit cutter, cut out rounds and place them on the prepared baking sheet. Gather remaining dough scraps and repeat until all dough is used.
08 - Brush the tops of the biscuits with extra buttermilk for a golden crust.
09 - Bake for 18 to 20 minutes, or until the biscuits are well-risen and golden brown.
10 - While the biscuits bake, combine the softened butter, honey, and a pinch of sea salt in a small bowl. Mix until smooth and creamy.
11 - Serve the biscuits warm, split and generously spread with honey butter.