1) Preheat oven to 350 degrees F. In a mixing bowl using a hand mixer or in the mixing bowl of a stand mixer, cream together butter and sugar until it’s nice and light.
2) Mix in eggs one at a time into the creamed butter and sugar. Then add vanilla and continue to mix.
3) Add in cocoa powder and a pinch of salt. Then add flour and mix until just combined. Try not to overmix the batter at this point.
4) Scoop batter into a 8×8 baking dish (buttered and dusted with cocoa powder) and spread out evenly with a flat spatula.
5) In a separate bowl, rinse and drain blueberries and toss them with 1 tablespoon sugar and 1 teaspoon cornstarch. Press blueberries into the brownie mix.
5) Bake brownies at 350 degrees for 25-30 minutes until the center is not quite set, but almost. Don’t over-bake them!
6) Let brownies cool for 15 minutes before slicing into them.
Optionally, drizzle with melted chocolate.
Store leftovers at room temperature in an airtight container.