Wash, hull and quarter the strawberries. In a mixing bowl, combine the strawberries with the sugar and lemon juice. Refrigerate until juices develop, at least 30 minutes.
1 1/2 lbs. fresh strawberries, 1/3 cup sugar, 2 Tbsp. fresh lemon juice
Preheat the oven to 425°F. Line a baking sheet with a silicone baking mat or parchment paper and set aside.
Combine the sugar and lemon zest together in a large bowl. Rub the sugar and lemon zest between your fingertips to create a lemon sugar. This helps release the natural oils and infuse more lemon flavor into the shortcakes.
3 Tbsp. sugar, 2 tsp. lemon zest (zest from 1 lemon)
Add the flour, baking powder, baking soda, and salt. Whisk to combine.
3 cups all purpose flour, spooned and leveled, 1 Tbsp. + 1 tsp. baking powder, 3/4 tsp. baking soda, 1/2 tsp. fine salt
Cube the cold butter into small pieces and add to the dry ingredients. Work the butter into the flour with your hands/fingertips until it's crumbly. See video for guidance. If you have warm hands and feel the dough got too warm, pop it in the fridge for a few minutes to chill.
10 Tbsp. unsalted butter, cold
Create a well in the middle of the flour and stream in the buttermilk, mixing together with a fork, wooden spoon or rubber spatula. Mix just until it begins to come together and a shaggy dough forms. We don't want to over mix it here, overworking the dough will result in dense, tough cakes. We want fluffy cakes!
1 cup buttermilk, cold
Pour the dough onto a clean, lightly floured work surface. Gently knead the dough, folding it over itself about 6-8 times until it comes together. You can use some extra flour on your hands as needed. Pat the dough into a rectangle, about 3/4-1-inch in thickness.
Using a 2 3/4-3-inch biscuit cutter, press the cutter straight down into the dough (do not twist). Bring together the scraps and continue pressing the biscuit cutter down into the dough. You should have ~8 shortcakes.
Place the shortcakes on the prepared baking sheet. Line them up next to each other. When the biscuits are touching, as opposed to being a few inches apart from each other, it helps them bake up nice and tall. It also prevents lopsided cakes.
Brush the tops of the cakes with heavy cream and a sprinkle of sugar, if using. Bake for 15-18 minutes, or until the biscuits are golden brown on top. Remove from the oven and cool.
1-2 Tbsp. heavy cream, coarse sugar, optional
Prepare the whipped cream: Using a hand held mixer or electric mixer with a whisk attachment, beat the heavy cream on medium-high speed until soft peaks begin to form, about 1-2 minutes. Then add in the powdered sugar, vanilla extract and sour cream and beat until medium peaks form.
1 cup heavy cream, cold, 2 Tbsp. powdered sugar, 1 tsp. vanilla extract, 1 Tbsp. sour cream
Assemble the shortcakes: slice the cakes in half, add a layer of whipped cream, strawberries on top then the other cake on top. Top with more whipped cream, strawberries and a dusting of powdered sugar. Serve immediatley and enjoy!