GO:0047277:   globoside alpha-N-acetylgalactosaminyltransferase activity
Catalysis of the reaction: N-acetyl-D-galactosaminyl-(1,3)-D-galactosyl-(1,4)-D-galactosyl-(1,4)-D-glucosylceramide + UDP-N-acetylgalactosamine = N-acetyl-D-galactosaminyl-N-acetyl-D-galactosaminyl-(1,3)-D-galactosyl-(1,4)-D-galactosyl-(1,4)-D-glucosylceramide + UDP.