Koruzna prga is a traditional festive bread originating from the Posavje region. It's made with a combination of corn flour, eggs, milk, baking powder, salt, and fat for greasing the baking tin. The scalded milk (or milk and cream) is poured over the corn flour, and it's then left to cool.

Baking powder and eggs are added to the mixture, which is then stirred until the batter becomes liquid. The batter is poured into a greased baking tin and incisions are then made on the top, always in the shape of a rectangular net. The bread is baked until golden brown.

Once baked, there should be a pattern of squares on the surface, which suggests how it should be broken before it's enjoyed, making it ideal for social events.