Preheat oven to 350°F and line an 8x8 square pan with parchment paper. Set aside.
In a large bowl, whisk melted butter, brown sugar, and white sugar until well combined.
1/2 cup butter, 1/2 cup brown sugar, 2/3 cups white sugar
Add in vanilla and eggs and continue whisking for 2 minutes until pale.
2 eggs, 1 tbsp vanilla
Add in flour, cocoa powder, and salt. Gently fold in until no flour streaks appear. Do not overmix.
3/4 cups all-purpose flour, 2/3 cups unsweetened cocoa powder, 1/2 tsp salt
Add in sliced strawberries and milk and dark chocolate chunks. Fold a few times.
5 strawberries, 1 cup milk and dark chocolate chunks
Spread the brownie batter evenly in the prepared pan. Top with extra berries and chocolate pieces. Bake for 20-22 minutes. The brownies will be ready when a toothpick inserted comes out moist with crumbs.
Allow the brownies to cool before slicing and enjoy!