Step 1: Preheat your oven to 400°F (200°C). Line a baking sheet with parchment paper.
Step 2: In a large bowl, whisk together the all-purpose flour, granulated sugar, baking powder, and salt.
Step 3: Add the cold, cubed butter to the flour mixture. Using a pastry blender, two knives, or your fingertips, cut the butter into the flour until the mixture resembles coarse crumbs with some pea-sized pieces of butter remaining.
Step 4: In a separate small bowl, combine the cold coconut milk and cold whole milk (or additional coconut milk).
Step 5: Pour the cold milk mixture into the dry ingredients, along with the shredded unsweetened coconut. Stir with a spoon or your hands just until a shaggy dough forms and no dry streaks of flour remain. Do not overmix.
Step 6: Turn the dough out onto a lightly floured surface. Gently knead it 3-4 times, just enough to bring it together. Pat or roll the dough into a 3/4 to 1-inch thick rectangle.
Step 7: Using a 2-2.5 inch round biscuit cutter, cut out biscuits. Press straight down without twisting. Gather the scraps, gently re-pat them, and cut out any remaining biscuits.
Step 8: Place the biscuits on the prepared baking sheet, leaving about 1 inch between them. For softer sides, place them closer together; for crispier sides, space them further apart.
Step 9: Bake for 18-20 minutes, or until the tops are golden brown and the biscuits are cooked through. If desired, brush the tops with melted butter immediately after removing from the oven for extra shine and flavor.
Step 10: Serve warm and enjoy!