1. Prepare the Strawberries: In a medium bowl, combine the hulled and sliced fresh strawberries with 2 tablespoons of granulated sugar. Gently toss to coat and set aside to macerate while you prepare the biscuits. This allows the strawberries to release their juices and create a delicious syrup.

2. Combine Dry Ingredients: In a large mixing bowl, whisk together the all-purpose flour, 1/4 cup granulated sugar, baking powder, baking soda, and salt. Make sure all dry ingredients are well combined to ensure even leavening.

3. Cut in the Cold Butter: Add the very cold, cubed unsalted butter to the dry ingredients. Using a pastry blender, two knives, or your fingertips, cut the butter into the flour mixture until it resembles coarse crumbs with some pea-sized pieces remaining. Avoid overworking the butter, as those small pieces will create steam and flakiness in the oven.

4. Add Wet Ingredients: Pour in the sourdough starter or discard and 1/2 cup of heavy cream. Mix with a fork or your hands until just combined. The dough will be shaggy and a little sticky, but avoid overmixing. Overmixing develops gluten, leading to tough biscuits.

5. Shape the Biscuits: Turn the dough out onto a lightly floured surface. Gently pat the dough into a 1-inch thick rectangle. Using a a 2.5-inch round biscuit cutter, cut out biscuits. Re-roll scraps gently once or twice to get more biscuits, but be careful not to overwork the dough. You should get about 8-10 biscuits.

6. Bake the Biscuits: Place the cut biscuits on a parchment-lined baking sheet, leaving about an inch between them. Brush the tops of the biscuits with the remaining 1 tablespoon of heavy cream and sprinkle lightly with granulated sugar. Bake in a preheated oven at 400 F (200 C) for 18-20 minutes, or until golden brown on top and cooked through. The biscuits should sound hollow when tapped on the bottom.

7. Assemble and Serve: Once baked, remove the biscuits from the oven and let them cool slightly on a wire rack. To serve, split a warm biscuit in half, spoon a generous amount of the macerated strawberries over the bottom half, top with the other biscuit half, and finish with a dollop of fresh whipped cream.