Slice strawberries into pointed strips (tip to base). Toss with sugar and orange juice in a large bowl. Cover and chill for 30 minutes or overnight, stirring occasionally.
Make the biscuits
Preheat oven to 500°F (yes, that's correct). Line a baking sheet with parchment paper.
Mix flour, sugar, baking powder, and salt in a bowl. Cut in cold butter until crumbly (or use frozen, grated butter and mix by hand). Add cold buttermilk and stir just until combined—the dough should be slightly wet and crumbly.
Lightly flour a parchment-lined surface. Roll dough into a ¾” thick rectangle. Cut into 12 squares or use a 3-inch biscuit cutter. Brush tops with buttermilk and sprinkle with turbinado sugar.
Place biscuits on the prepared baking sheet. Bake for 14–15 minutes until golden (check at 10 minutes). Cool biscuits, then transfer to a wire rack.
Assemble shortcakes
Slice each biscuit in half. Layer whipped cream and strawberries on the bottom half, then top with the other half. Finish with more cream, berries, and a mint sprig. Serve immediately.
Notes
For more details on this recipe, see the post for tips and variations.