For the Biscuits

1. Preheat the oven to 425°F and line a baking sheet with parchment paper.
2. Freeze the butter for 10 minutes, then grate it using a cheese grater.
3. Toss the rinsed and dried blueberries with 1 teaspoon of flour to prevent excess moisture.
4. In a mixing bowl, combine flour, baking powder, salt, and sugar. Add the grated butter and mix gently.
5. Pour in the buttermilk and stir until just combined. Fold in the blueberries carefully.
6. Drop the dough by ¼-cup portions onto the baking sheet, making sure the biscuits are touching.
7. Bake for 15–18 minutes or until golden brown and cooked through.

For the Glaze (Optional)

1. Whisk powdered sugar, melted butter, milk, and vanilla extract until smooth.
2. Drizzle over the biscuits before serving, while warm or cooled.