Ingredients

• 250 grams (or 8.8 oz) of white chocolate, chopped
  
• 113 grams (or 1/2 cup) of unsalted butter
  
• 100 grams (or 3.5 oz) of dark brown sugar
  
• 4 eggs
  
• 60 grams (or 2.1 oz) of plain flour
  
• 2 teaspoons of vanilla extract (can be replaced by a vanilla bean)
  
• 1 teaspoon of kosher salt
  
• 100 grams (or 3.5 oz) of fresh blackberries, roughly chopped (you could also use frozen ones or even blackberry jam)