Cry after doing something impressive

• "I'm do-o-one!"
• Cry frequently made with jazz hands
• Vocalized fanfare
• Invitation to be impressed
• 'And there you have it!'
• Kin of "voila!"
• "I'm finally done!"
• Bit of mock vocal fanfare
• Kin of "presto!"

Wiktionary Word definitions in Wiktionary
interj. (alternative spelling of ta-da English)