Cook almond bark in a slow cooker on High, uncovered and stirring occasionally, until mostly melted, 5 to 10 minutes. Reduce the heat to Low and stir in chocolate chips. Cook and stir until chips are melted and mixture is dark in color, 5 to 10 minutes.

Turn off the heat and stir in peanuts. Drop a spoonful onto a piece of parchment paper to test consistency; it should be thick and chunky. If it's too loose and runny, stir in more chocolate chips and peanuts.

Line several baking sheets with parchment paper. Use a melon baller to drop spoonfuls peanut mixture onto the prepared baking sheets. Let harden before serving, about 1 hour.