Preheat your oven to 350°F (175°C). Grease a 9x13-inch baking pan or line it with parchment paper.
In a large mixing bowl, combine the melted butter and granulated sugar. Mix until well combined. Add the eggs one at a time, mixing well after each addition. Stir in the vanilla extract.
In another bowl, whisk together the flour, cocoa powder, salt, and baking powder. Gradually add the dry ingredients to the wet ingredients, mixing until just combined. Do not overmix.
Fold in the sliced strawberries gently, being careful not to break them apart. Pour the brownie batter into the prepared baking pan and spread it evenly.
Bake in the preheated oven for 25-30 minutes, or until a toothpick inserted into the center comes out with a few moist crumbs. Allow the brownies to cool completely in the pan.
While the brownies are cooling, melt the chocolate chips and vegetable oil together in a microwave-safe bowl in 30-second intervals, stirring in between until smooth.
Once the brownies are cool, pour the melted chocolate over the top and spread it evenly. Allow the chocolate to set for about 30 minutes at room temperature or refrigerate for quicker setting.
Cut into squares and serve.