Brownie Cookie Sandwich with Peanut Butter Frosting

Bahan-bahan (10 porsi)

• 1 stick / 1/2 cup / 115g unsalted butter (, cut into chunks)
• 10 oz / 300g dark chocolate chips ((or buttons, melts or block chocolate cut into chunks))
• 1 cup + 2 tbsp caster sugar
• 3 eggs
• 2 tbsp cocoa powder
• 1 tsp vanilla extract
• 1/2 tsp salt
• 1/2 tsp baking powder
• 3/4 cup plain flour
• 1/2 cup dark chocolate chips
• 1 cup smooth peanut butter
• 1 cup confectioners' sugar ((icing sugar))
• 2.5 oz / 5 tbsp / 70g / 2/3 stick unsalted butter (, softened)
• 3/4 tsp vanilla extract
• 1/4 tsp salt
• 1/3 cup heavy cream ((unwhipped pouring cream))