I bought cook serve delicious a while ago from their website before I got steam. Now that I have steam installed, I'd like to have cook serve delicious in my library; however obviously I don't want to have to buy the game again. I have the original installer .exe file that I downloaded when I bought the game. Is there any way I can use this to install my game into my steam library so it can receive the full benefits that steam provides (automatic updates etc.)?
Unfortunately not. Although you can add a shortcut to the game on Steam and the Steam overlay will even show up, that still doesn't do much and it's still a non-Steam game.
However, chances are that you may have received a redeemable Steam code with your order, or that you may have one accessible somewhere with your purchase.