Preheat the oven to 400 degrees F & prepare a baking sheet by covering the sheet with a piece of parchment paper, set aside.
In a medium bowl, whisk together the flour, baking powder, sugar and salt.
Using a pastry blender, your hands, or a knife and fork, cut in the butter until the flour resembles coarse crumbs.
Add the lemon zest and toss to combine. Stir in milk, lemon juice & vanilla until well combined and dough starts to come together.
Once it starts to stick together add in 6 ounces of fresh blueberries, knead together. Remove it from the bowl and knead together it on a floured surface, 5 or 6 times.
Then roll into a 1-inch-thick disc. Using a 3-inch biscuit cutter cut out biscuits. Knead the scraps together, re-roll and cut out rounds until all the dough has been used.
Place the biscuits on a prepared baking sheet. Brush each biscuit with milk and sprinkle with sugar. Bake until the tops are golden brown, about 18-22 minutes. Let biscuits cool completely on the baking sheet.
Prepare whipped cream while biscuits are cooling.
Using a hand mixer or stand mixer, add heavy whipping cream and sugar, beat on high for 4-6 minutes until cream is whipped and soft peaks form, I like mine peaks firm, so I beat for another minute after that.
To prepare shortcakes, cut biscuits using a serrated knife, top the bottom halves with whipped cream, then top with the blueberries. Add the top half of the shortcake and sprinkle with lemon zest. Serve immediately.