"My dad eats dumplings with cabbage."
Translation:Мій тато їсть вареники з капустою.
I thought so as well. I missed this question because I selected only the "dad" option instead of the "dad" and "father" options.
Why doesnt вареники in мій тато їсть вареники з капустою have the -у ending since its supposed to be in accussative form
Only feminine nouns change endings in accusative. Since вареники is not feminine it doesn't change. I think you can verify this in Tips&Notes for Accusative.
"вареники" are in acc (їсть що? (what?) вареники), капуста is in instrumental (вареники з чим? (with what?) з капустою)