Preheat oven to 425*
In a large bowl, mix together flour, baking powder, salt, and sugar. Use a dough cutter to cut in cold butter until mixture resembles cornmeal.
Add blueberries and stir until well coated with flour mixture.
Gradually, add milk and use a silicone spatula to stir mixture until completely incorporated.
Turn onto a floured surface and pat down until you form a slab 1/2 inch thick. Use a biscuit cutter or glass to cut biscuits. Repeat until all dough is used, you should end up with 6 or 7 biscuits.
Bake for 13-15 minutes.
Meanwhile, in a small bowl combine powdered sugar and vanilla, gradually add milk until icing is the desired consistency.
Drizzle on top of warm blueberry biscuits to serve.