Stir the strawberries and 1/4 cup (50g) granulated sugar together in a large bowl. Cover and set in the refrigerator until ready to use. This time allows the strawberries to release their delicious juices.

Preheat oven to 400°F (204°C). Mix the flour, granulated sugar, baking powder, baking soda, and salt together in a large bowl or in a large food processor. Whisk or pulse until combined. Add the cubed butter and cut into the dry ingredients with a pastry cutter or by pulsing several times in the processor. Pulse until coarse crumbs form. If you used a food processor, pour the mixture into a large bowl.

Pour buttermilk on top. Fold everything together with a large spoon or silicone spatula until it begins to come together. Do not overwork the dough. The dough will be shaggy and crumbly with some wet spots. Pour the dough and any dough crumbles onto a floured work surface and gently bring together with generously floured hands. Have extra flour nearby and use it often to flour your hands and work surface in this step. Using floured hands or a floured rolling pin, flatten into a 3/4 inch thick rectangle as best you can. Fold one side into the center, then the other side. Turn the dough horizontally. Gently flatten into a 3/4 inch thick rectangle again. Repeat the folding again. Turn the dough horizontally one more time. Gently flatten into a 3/4 inch thick rectangle. Repeat the folding one last time. Flatten into the final 3/4 inch thick rectangle.

Cut into 2.75 or 3-inch circles with a biscuit cutter. (Tip: Do not twist the biscuit cutter when pressing down into the dough.) Re-roll/flatten any scraps and cut more circles until you have around 10-12 biscuits.

Arrange in a 10-inch cast iron skillet (see note) or close together on a parchment paper or silicone baking mat lined baking sheet. Make sure the biscuits are touching.

Brush the tops with 2 Tablespoons heavy cream or buttermilk and sprinkle with coarse sugar. Bake for 18-22 minutes or until biscuits are golden brown on top. Remove from the oven, then cool in the pan for at least 10 minutes before assembling.

Using a hand mixer or a stand mixer fitted with a whisk attachment, beat the heavy cream, 2 Tablespoons granulated sugar, and vanilla on medium-high speed until soft-medium peaks form, about 3 minutes.

Slice the biscuits in half and layer with strawberries and whipped cream. Serve immediately.