Mix together a Betty Crocker Chocolate Cake mix, toss it into your slow cooker, then grab a can of Betty Crocker chocolate frosting.
Spoon giant mounds of frosting all over the top of the cake batter. Make sure you get the edges! We need to ensure proper lava-liciousness all over the cake.
Cover and cook on high for about 2-3 hours. Time will vary slightly depending on your slow cooker, but you'll know it's done because the edges will spring back when touched lightly with a finger, and the center will be gooey but not batter-like.