Heat your oven to 325 degrees. Line 2 cookie sheets with parchment paper and set aside. 

In a large bowl cream together the butter and powdered sugar. Add the sugar a little at a time so it doesn't get white powder all over ;)

Add the cocoa and salt (I put in a sifter and sifted it into the bowl). You can also just put the cocoa and salt in a bowl and whisk it till there are no lumps then add to the butter till smooth.

Add the sour cream & vanilla and mix till just combined. Slowly at the flour on low until no streaks remain then stir in the chocolate chips!

Form into balls then roll into the cocoa powder. I used a cookie scoop, then rolled into a ball and then rolled in the cocoa powder. Place on the prepared baking sheets and bake for 8-9 minutes for smaller balls (if you use a small cookie scoop, about 1") or 9-10 minutes for medium sized cookie. The cookies will still look a little wet from the cocoa powder, but don't over bake them or they will be dry. Take them out with they just barely took set. (The cookies don't flatten much, they should stay in a nice truffle shaped mound. If they flatten you may need to add a little more flour to your dough. For best results, it's best to measure out the ounces of flour so you know you added the right amount.)

Let the cookies cool for 5 minutes before transferring them to a wire rack to cool completely. When they are cool, roll them in the powdered sugar. Store in an airtight container. 

Makes about 4 to 5 dozen, depending on the exact size you make.