A large surplus of anything:
We've got enough coffee to cobble dogs with.
A cobblestone is a cut stone with a curved surface. These were set together to create road surfaces, in the days before the widespread use of asphalt. The image the phrase contains is that, even after all the roads have been cobbled, there are so many cobblestones left over that things that don’t need cobbling – such as dogs – could still be cobbled.
A cobbler repairs shoes, so if you have enough leather to cobble an animal with four feet or that doesn't need shoes, you have a surplus.