Lara Clarke, from Walsall, won the award at the Cake International contest with her 5ft 10in (1.7m) creation, inspired by the Hunger Games star.
Ms Clarke previously triumphed at the contest with a life-sized Johnny Depp cake, which made headlines around the world.
She said she found her second consecutive success "hugely exciting".
Ms Clarke also won silver in the large decorative exhibit section at the competition, with a cake based on her favourite Game of Thrones character Tyrion Lannister.
She spent two-and-a-half months working on the cakes ahead of the competition at Birmingham's National Exhibition Centre,
The Jennifer Lawrence sponge cake required 150 eggs, 10kg (22lb) flour and 10kg butter.
When asked what she planned to enter next  year, she said she would need a "long lie down" before she decided.
Clare Fisher, senior sales executive at Cake International, said the standard of entries was "breathtaking".
A woman has won a gold award at national baking competition by entering a life-sized Jennifer Lawrence cake.