Yes indeed!

yes, indeed(y)

informal A more emphatic way of saying "yes." A: "Are you going to the party tonight?" B: "Yes, indeed. Probably going to head over there around 9 or so." Yes, indeedy, I truly believe that this is the finest pizza in all of New York City!
Farlex Dictionary of Idioms. © 2015 Farlex, Inc, all rights reserved.

Yes indeed(y do)!

Inf. Definitely yes! Tom: Will you marry me? Jane: Yes indeedy do, I will! Charlie: Did your horse win the race? Bill: Yes indeedy!
See also: yes
McGraw-Hill Dictionary of American Idioms and Phrasal Verbs. © 2002 by The McGraw-Hill Companies, Inc.
See also:
References in periodicals archive ?
Yes indeed! In the last few days, education officials have bemoaned the over-use or abuse of the humble exclamation mark.
RUPERT MOON Yes indeed! It's a massive challenge but I''''m a believer!
Yes indeed! As much as what he engineered was horrible, even evil, it is equally evil to celebrate this death.
83) Yes indeed! Don't, however, assume that the author is simply there to lecture at the reader.