Funfetti Birthday Sheet Cake - Sally's Birthday Cake!

There are 2 birthdays in the Cupcake Jemma team this week - Sally & Sam are both celebrating so OBVIOUSLY a cake was needed, and sometimes, a single layer of deliciously moist vanilla funfetti cake, topped with silky swiss meringue buttercream does the trick!
Funfetti Birthday Sheet Cake - Sally's Birthday Cake!