Yup!
The range had to be modified for the famous "monster loaf" scene- the oven's back had to be cut out so that prop men could shove the enormous loaf of bread at Lucille Ball. The oven was rigged with a wooden platform and rollers inside to make the loaf ride out smoothly. The loaf of bread itself was custom-baked by a commercial bakery called the Union Made Bakery. The pan in which it was baked also had to be custom-made (and paid for by Desilu), because no suitable pan existed. At the suggestion of the baker, the loaf was rye bread, because the loaf had to hold up for several days of rehearsal and then shooting; rye bread stays fresh longer than white. After the episode was "in the can", the bread was cut up and distributed to cast and crew.
The way all of this was done is one of the reasons that I Love Lucy still holds up today. Virtually every other comedy show of the era would have elected to use a papier-mache loaf, but Ball always insisted that props and settings have as much reality as possible. Her insistence on real bread cost Desilu a lot of money (which came partially from her own pocket as part-owner of the company), but Ball was not comfortable around fake props, feeling that they were a cheat to her as an actress who had the responsibility to create reality, and to the audience. You only have to look at other big shows of the time to see how smart she was; on the Colgate Comedy Hour, for instance, they used a lot of cheap, fake sets and props, with the result that the shows look very dated today, even with the genius of Jerry Lewis and Dean Martin. I Love Lucy, on the other hand, looks timeless.
The info on how the bread stunt was done is from The "I Love Lucy" Book, by Bart Andrews.