I haven't had any luck finding a bank/credit union who offers this product. Did banks/credit unions stop offering this post recession? If not, can someone point me in the right direction?

Unsecured loans are quite common, but maybe not what you're hoping for.

1st, don't tell them it's for a house or for real estate investing.

2nd, most of these types of loans are for 15-30K. and usually for borrowers with liquid assets of considerable amount relative to the borrowed amount. for instance if you want to borrow 20K, the bank might require you have 15K in cash already.

This is the riskiest type of loan for a bank. So the terms are going to be TIGHT.

@William S. Yes, there are loans available but the metrics will depend on your particular situation.  I have a $100k+ unsecured loc.  It is based on my business/real estate history, cash reserves, and total portfolio equity.  

Look at your small, local, business banks. Take your written history, tax returns, p&l’s, etc..  and schedule a meeting with the business loan officer of the bank. Get to know them and let them get to know you and what makes you tick.  The more defined your goals are and how you will use the $, the sooner you will get access to It! 

Good luck!