Not surprisingly, given the difficulty of this one, I learned a slightly different variation.
Betty Botter bought some butter,
"But", she said, "this butter's bitter.
If I bake this bitter butter,
It would make my batter bitter.
But a bit of better butter,
Would make my bitter batter better."
So Betty Botter bought a bit of butter,
Better than her bitter butter,
Baked it in her bitter batter,
And made Betty Botter's bitter batter better.
buh buh buh...