First, I like to gather all my ingredients in one place—it makes the process smooth and fast. Preheat your oven to 350°F (175°C) and grease a 9x13-inch baking dish. A little bit of prep now ensures that your cake doesn’t stick later.

Start by spreading the dry chocolate cake mix evenly across the bottom of your baking dish. Then, pour the milk directly over the cake mix. The milk will soak into the cake mix, which will help it form a moist, gooey layer during baking.

Next, drizzle the melted peanut butter over the cake mix and milk. If you’re a peanut butter fan like me, this step is incredibly satisfying. I love watching the peanut butter spread out, covering the chocolate layer beneath it. You don’t need to stir—just let it sit as it is.

Pour the melted butter over the entire dish, covering as evenly as possible. The butter helps create a wonderfully rich and gooey texture in the cake. After that, sprinkle the halved mini Reese’s Peanut Butter Cups across the top. Try to spread them out so that every bite has some Reese’s goodness.

If you’re craving a bit more chocolate (like I often do), sprinkle a handful of semi-sweet chocolate chips on top. They add an extra layer of indulgence that melts beautifully into the cake. Trust me, this simple addition is worth it!

Now, it’s time to let the oven do its magic. Place the baking dish in the preheated oven and bake for about 30-35 minutes. Keep an eye on it—when the edges look set and the center is still slightly gooey, it’s ready to come out. I’ve found that a slightly undercooked center gives this cake its signature gooey texture.

Once out of the oven, let the cake cool for just a few minutes. While it’s still warm, serve up big spoonfuls. The peanut butter, chocolate, and melted Reese’s will be gooey, rich, and irresistible. Sometimes I top it with a scoop of vanilla ice cream, which melts into the cake and adds a creamy contrast to the chocolate and peanut butter.