Haigh's Chocolates Make Haigh's Chocolate Speckle Marble Cake

Ingredients

• 150g Haigh dark pastilles, roughly chopped
• 1¼ cups (310ml) buttermilk
• 250g unsalted butter, diced
• 1 1/3 cup (295g) caster sugar
• 1 tbsp vanilla extract
• 4 extra-large eggs
• 2 ¼ cups (335g) self-raising flour
• ½ teaspoon salt flakes
• 440g Haigh’s milk chocolate speckles, to decorate
• 150g unsalted butter, at room temperature
• 3 cups (480g) icing sugar, sifted
• 2 tablespoons milk
• 1 tablespoon vanilla bean paste