1. Line a baking sheet with parchment paper. Whisk together the flour, cinnamon, baking soda and salt in a medium bowl.
2. Beat the brown sugar, granulated sugar, butter and yogurt with an electric mixer on medium-high speed in a large bowl until well combined, about 2 minutes.
3. Add the flour mixture, and mix on low speed until well incorporated. (Turn off the mixer and use your hands to help combine if needed.)
4. Scoop tablespoonfuls of the dough, and roll them into smooth balls. Put them on the prepared baking sheet, and refrigerate until chilled, about 1 hour.
5. Melt the chocolate chips and shortening in a medium microwave-safe bowl in the microwave in 30-second increments, stirring in between, until the coating is smooth and thin.
6. Drop the chilled balls into the coating, and roll them around with a fork to fully coat. Remove each truffle with the fork, letting any excess coating drip off, and return to the baking sheet. (If the coating begins to harden, microwave it for a few seconds to warm it up and thin it out.)
7. Chill the truffles until the coating is completely set, about 1 hour. (The truffles can be refrigerated in an airtight container for up to 5 days.)