This quick and easy chocolate dessert is made with just 3 store-bought ingredients plus the egg and oil you need for the brownie batter. They're incredibly fun and simple to make in a muffin tin! This is seriously the BEST dessert recipe I've ever made (probably in the history of the world!). They remind me of a fancy lava cake or mini pizookie served warm with ice cream. It's basically the marriage of a cookie, brownie and Reese's peanut butter cup. How can you go wrong with that?