Review the original item:
As Irene scooped stuffing from the Thanksgiving turkey, gold glinted in
the breadcrumbs,
finally, the earring that she had lost early that morning reappeared.
You wanted to fix it this way:
As Irene scooped stuffing from the Thanksgiving turkey, gold glinted in
the breadcrumbs finally, the earring that she
had lost early that morning reappeared.
To delete the comma between breadcrumbs and finally would cause an equally bad problem, a fused sentence. A fused sentence occurs when you have two main clauses joined with no punctuation whatsoever. Gold glinted in the breadcrumbs is the first main clause. Finally, the earring that she had lost early that morning reappeared is the second main clause.
The spot between breadcrumbs and finally needs a stronger break than blank space.
You might want to consult the rules for fixing comma splices and fused sentences.