Preheat your oven to 350°F (175°C). Grease a 9x13 inch baking pan or line it with parchment paper for easy removal.

In a medium saucepan over low heat, melt the butter and chopped chocolate together, stirring until smooth. Remove from heat and let it cool slightly.

In a large mixing bowl, whisk together the sugar, eggs, and vanilla extract until well combined. Slowly add the melted chocolate mixture, stirring until fully incorporated.

Sift in the flour and salt, mixing just until combined. Be careful not to overmix.

Gently fold in the sliced strawberries and chocolate chips if using.

Pour the brownie batter into the prepared baking pan, spreading it evenly.

Bake for 25-30 minutes or until a toothpick inserted into the center comes out with a few moist crumbs.

Allow the brownies to cool in the pan for at least 15 minutes before slicing into squares. For best results, chill in the refrigerator for an hour before serving.