Prepare the shortcakes: Preheat an oven to 400 degrees F. Whisk together the dry ingredients in a medium bowl. Combine the buttermilk and vanilla in a measuring cup and set aside. Grate the frozen butter on a box grater and gently fold it into the dry ingredients. Create a well in the center and add the buttermilk. Fold gently until a shaggy dough forms. Knead a couple of times by hand in the bowl until the dough comes together.

On a lightly floured surface, pat the dough into a square about 1" thick. Use a bench scraper to square up the edges and cut them into 4 equal-sized squares. Place them on a parchment-lined baking sheet and freeze for 15 minutes.  Brush the tops with heavy cream and sprinkle with sugar. Bake for 16 minutes or until the shortcakes are cooked through and lightly golden. Cool before slicing.

Prepare your strawberries: combine the strawberries in a bowl with the sugar, lemon juice, and vanilla and gently toss until well-mixed. Set aside.

For the whipped cream: Combine ingredients in a mixing bowl and whisk until soft peaks form.

Assemble: Cut the shortcakes in half and top each half with a dollop of whipped cream, some of the strawberries with their juices, and the other half of the shortcake. Serve immediately.