This is the heartwarming moment a lucky birthday girl found a $30k cash surprise hidden inside a cake given by her boyfriend.

Video taken on February 23 in Bangkok, Thailand shows the woman digging through the 11-pound dessert with her bare hands to reach the stack of banknotes worth one million baht (about $30.5k).

With icing-caked fingers, she tore through the plastic bag placed inside and happily held up the hefty bundle of cash.

Janwatida Thainta, owner of the bakery that made the cake, said a 35-year-old male customer who asked to remain anonymous walked into her shop and requested a three-tiered cake in which money could be hidden.

She added that the staggering amount of money was planned to be given via digital bank transfer, but the client decided to bring it to the store in person instead.

She said: 'What surprised me was that he was so nonchalant while handing me the one million baht to be hidden in the cake. Thank you so much for your trust. I put every single bill inside the cake, as requested.'