Preheat your oven to 350°F (175°C) and grease a 9x13-inch pan.

Melt the butter in a saucepan, then stir in the sugar until it looks like wet sand.

Add eggs one at a time, mixing well after each, until the batter is glossy and thick.

Stir in vanilla.

In another bowl, whisk together flour, cocoa, salt, and baking powder.

Gently fold the dry ingredients into the wet mixture, then stir in chocolate chips.

Pour the batter into the greased pan and smooth the top.

Bake for 25–30 minutes until the center springs back slightly and a toothpick has a few moist crumbs.

Let the brownie cake cool completely.

Heat heavy cream in a saucepan until tiny bubbles form around the edges, but do not let it boil.

Place chopped chocolate in a heatproof bowl, then pour the hot cream over it and let it sit for 2–3 minutes.

Stir the mixture gently until smooth, shiny, and velvety.

Once the brownie cake is cooled, pour the ganache evenly over it and smooth with an offset spatula.

Decide to leave it at room temperature for a soft topping or chill in the fridge for 1–2 hours for a firm layer.

Slice into squares and serve with toppings like whipped cream or fresh berries.