Directions:
1. Preheat the oven to 425°F (220°C). Line a baking sheet with parchment paper.
2. In a large bowl, whisk together the flour, sugar, baking powder, and salt.
3. Cut in the cold butter using a pastry cutter or your fingers until the mixture resembles coarse crumbs.
4. Gently stir in the buttermilk and vanilla extract until just combined. Fold in the blueberries, being careful not to crush them.
5. Turn the dough onto a lightly floured surface and gently knead it 2-3 times. Pat the dough into a 1-inch thick circle.
6. Use a round biscuit cutter to cut out biscuits. Place them on the prepared baking sheet, leaving space between each.
7. Bake for 12-15 minutes, or until the biscuits are golden brown on top.
8. Make the Glaze: In a small bowl, whisk together the powdered sugar, milk, and vanilla extract until smooth. Drizzle over the warm biscuits