Preheat the oven to 425 degrees F (220 degrees C).

Toss together strawberries with 1/2 cup confectioners' sugar in a medium bowl until evenly coated. Let sit at room temperature until juices form, about 1 hour.

Whisk together flour, white sugar, baking powder, and sea salt in a large bowl until well blended. Cut in butter with a pastry blender or 2 knives until mixture resembles coarse crumbs. Pour in 1 cup cream, starting with 1/2 cup and adding 1 to 2 tablespoons at a time as needed. Stir to make a soft dough, adding more cream as needed. Place dough into a floured bowl and knead a few times with the heel of your hand.

Roll dough out 1/2 inch thick on a floured surface; cut dough into six 3-inch rounds using a biscuit cutter. Place onto an ungreased baking sheet.

Bake in the preheated oven until tops are golden brown, 10 to 12 minutes. Cool shortcakes on a wire rack.

Beat together remaining 1 cup cream in a metal or glass bowl with an electric mixer until soft peaks form. Fold in 2 tablespoons confectioners' sugar and vanilla until incorporated. Cover and refrigerate whipped cream until ready to serve.