8. Leave the whole thing in the tin until completely cold, then, if you’re using the brownie tin, lift up the protruding rim slightly and slide the uncut brownie out on its base. If you’re using a normal tin, lift out the brownie with the foil. Cut into quarters, then cut each quarter into four squares and finally into triangles. These brownies are so addictive you’ll want to make a second batch before the first is finished, but if you want to make some to hide away for a special occasion, it’s useful to know that they’ll keep in an airtight container for a good two weeks and in the freezer for up to a month.