Turn up the birthday celebrations with our Personalised Retro Cassette Birthday Letterbox Brownies from bakerdays! Featuring a colourful collection of vintage cassette tapes, bold birthday lettering and nostalgic 80s-inspired designs, these delicious brownies are perfect for music lovers, retro enthusiasts and anyone who loves a throwback. Personalise them with a name and special message to create a fun and memorable birthday surprise.