Directions

1. 1

   Preheat your oven to 180°C (350°F). Prepare a rectangular baking pan by greasing it thoroughly and lining it with parchment paper, ensuring the paper extends up the sides for easy removal.

2. 2

   In a large mixing bowl, cream the butter by beating it for about 2 minutes until it lightens in color and becomes fluffy and pale.

3. 3

   Add the vanilla extract, salt, and all 250g of sugar to the creamed butter. Continue beating until the mixture is light and well combined.

4. 4

   Incorporate the eggs one at a time into the butter-sugar mixture, beating well after each addition to fully incorporate before adding the next egg.

5. 5

   In a separate bowl, whisk together the flour and baking powder until well combined.

6. 6

   Add the flour mixture to the butter mixture in alternating additions with the milk, starting and ending with the flour. Mix until just combined, being careful not to overmix.

7. 7

   Divide the batter into two equal portions. To one portion, stir in the cocoa powder and rum until smooth and thoroughly blended. Leave the other portion plain for the vanilla batter.

8. 8

   Pour the vanilla batter evenly into the prepared baking pan, spreading it to cover the bottom in an even layer. Then pour the chocolate batter on top.

9. 9

   Using a butter knife or skewer, gently drag it through the two batters in a back-and-forth motion to create a marbled pattern throughout the pan.

10. 10

    Place the pan in the preheated 180°C (350°F) oven and bake for approximately 60 minutes, until a toothpick or wooden skewer inserted into the center comes out clean or with just a few moist crumbs.

11. 11

    Remove the brownies from the oven and allow them to cool completely in the pan. Once cooled, cut into 18 equal squares and serve.