01 -
Preheat the oven to 175°C. Grease a 23x33 cm baking pan and line it with parchment paper.
02 -
Melt the butter over low heat, then remove from heat and stir in 400 grams sugar until combined.
03 -
Incorporate eggs one at a time, mixing thoroughly after each addition, then stir in vanilla extract.
04 -
Whisk flour, cocoa powder, salt, and baking powder in a separate bowl until evenly blended.
05 -
Gradually fold the dry ingredients into the butter mixture until just incorporated, avoiding overmixing.
06 -
Blend raspberries with sugar and lemon juice until smooth, then strain through a fine-mesh sieve to remove seeds.
07 -
Pour batter evenly into the prepared pan. Spoon raspberry puree over the batter and use a knife or toothpick to create a swirl pattern.
08 -
Bake for 30 to 35 minutes, or until edges are set and a toothpick inserted in the center comes out with moist crumbs.
09 -
Let cool completely in the pan before slicing into squares and serving.