Position racks to divide oven in thirds; preheat to 325 degrees F. Line two baking sheets with parchment paper.
In a food processor add almonds and sugar; process until the almonds are mostly ground, scraping the bowl occasionally to ensure you don't have a thick layer on the bottom. Add flour, cocoa, salt, and cinnamon; pulse to combine mixture. Scatter bits of cold butter over mixture and process in long pulses until you have moist curds and crumbs. (This might take a couple of minutes.) Scrape sides and bottom of bowl as needed, and check dough often by pinching a piece to see if it holds together. Add the chocolate; process for a couple pulses until combined. Shape the dough into a ball.
For each cookie, squeeze about a teaspoon of dough into a nugget, pyramid, or random shape. Place on the baking sheets with a little space between (they don't spread much during baking).
Bake cookies about 15 minutes (rotate sheets top to bottom and front to back after 8 minutes). Cookies will be very soft, but they'll firm as they cool. Cool on baking sheets for 5 minutes; gently transfer cookies to wire racks to cool.