Preheat your oven to 475ºF. Line a baking sheet with parchment paper or lightly grease it. Alternatively, you can use a greased 12-inch cast iron skillet for a more traditional presentation.

In a large mixing bowl, whisk together the self-rising flour, baking powder, and granulated sugar until well combined and no lumps remain.

Using a box grater, grate the frozen butter directly into the flour mixture. Toss gently to coat the butter shreds with flour. Place the bowl in the freezer for 10 minutes to keep everything cold.

Remove the bowl from the freezer and gently fold in the fresh blueberries until they’re evenly distributed throughout the flour mixture.

Create a well in the center of the dry ingredients and pour in the chilled buttermilk. Using a wooden spoon or spatula, stir gently until the dough just comes together. Be very careful not to overmix—the dough should look shaggy.

Turn the dough out onto a lightly floured surface. Gently pat it with your hands to about 1-inch thickness. Do not use a rolling pin, as this will deflate the dough and result in less fluffy biscuits.

Using a biscuit cutter or a sharp knife, cut out biscuits from the dough. Gently reshape scraps as needed, working the dough as little as possible to maintain its tender texture.

Place the dough rounds on your prepared baking sheet or skillet. Bake for 20-26 minutes, or until the tops are golden brown and the biscuits have risen beautifully.

Remove the biscuits from the oven and immediately brush the tops with melted butter. Allow them to cool for a few minutes on the pan, then transfer to a wire cooling rack.

In a small bowl, combine powdered sugar, lemon juice, vanilla extract, and milk. Mix until smooth and well combined. Transfer the icing to a ziploc bag, snip a small corner, and drizzle over the cooled biscuits.