Preheat oven to 425°F (220°C) and line a baking sheet with parchment paper.

In a large mixing bowl, whisk together the flour, sugar, baking powder, baking soda, salt, and lemon zest.

Incorporate the cold cubed butter into the dry ingredients using a pastry blender or two knives until the mixture resembles coarse meal with pea-sized lumps.

Gently fold the fresh blueberries into the flour mixture until evenly distributed.

Create a well in the center and pour in the cold buttermilk. Stir with a fork until a shaggy dough just begins to form.

Transfer the dough onto a lightly floured surface. Gently pat into a rectangle and fold it over itself three times to create layers.

Flatten the dough to a 1-inch thickness and cut biscuits using a 2.5-inch circular cutter, pressing straight down without twisting.

Place biscuits on the prepared baking sheet, brush the tops with melted butter, and bake for 15 to 18 minutes until golden brown and risen.