The episode you have in mind is called "Insane Clown Poppy," and it
was initially broadcast by Fox on November 12, 2000.
Here is my authoritative source for that information:
"At Timothy Lovejoy's stand, he's promoting his book "Someone's in the
Kitchen with Jesus". Marge tries a stigmuffin, and Homer tries Mary
Magdalene's chocolate orgasm, an eclair. When Homer bites it, the
filling squirts out of it and hits Tom Wolfe's white suit. He tears off
the suit revealing an identical suit underneath."
The Simpson's Archive: Insane Clown Poppy (November 12, 2000)
The above is a text file that is not reader-friendly, but you will
find the plot summary excerpt in question about two-thirds of the way
down the page.
Here is a link to a more readable summary of the episode's plot
(although it doesn't include the small detail involving the Tom Wolfe
TV Tome: The Simpsons: Insane Clown Poppy: Episode 251: November 12, 2000
I used the following Google search to find the information:
"the simpsons" "episode guide"
There are several online episode guides for the show. Luckily, the
one appearing at the top of the "hit" list for the search was the one
that described this particular detail. I found it at the Simpson's
Archive site by searching its contents for references to "tom wolfe,"
and this was the only one there.
I then double-checked the information by conducting another Google
search armed with the more specific search terms "insane clown poppy"
and "tom wolfe" and found a corroborating reference on French website:
Simpsons Park: Retranscription des Episodes
I am confident that this is the information you are looking for, and I
am happy to be able to get it to you promptly. If anything is
unclear, please ask for clarification before rating the answer.