My uncle makes this every June for our family cookouts and people always beg for the secret. Takes only 3 ingredients to make this summer hit.

My uncle Ray has been hauling his old black slow cooker to our June cookouts since the late 80s, and every year this bright blue “ocean water” dump cake disappears before the burgers are off the grill. Nobody can believe it’s just three pantry ingredients and a plug-in crock. The color is pure summer—lake days and swimming pools—and the texture is that cozy, old-fashioned dump cake crumble, only soaked in a fizzy, tropical-scented syrup with sweet coconut on top. It’s the kind of no-fuss dessert you can throw together in five minutes, let it bubble away while you visit on the porch, and then carry right out to the picnic table, slow cooker and all, to a chorus of, “What’s your secret?”

Serve this slow cooker ocean water dump cake warm right out of the crock, with big spoonfuls scooped into bowls so you catch both the crumbly blue cake and the clear, bubbling syrup from the bottom. A scoop of vanilla ice cream or a dollop of whipped topping melts into the warm cake and tastes like an old-fashioned soda fountain float. It pairs nicely with simple cookout fare—grilled brats, burgers, baked beans, and a crisp lettuce salad—because it’s light, fruity, and not too heavy after a plate of picnic food. A pot of coffee or tall glasses of iced tea on the side make it feel like a proper Midwestern summer gathering.

Servings: 8-10

1 (20-ounce) can pineapple tidbits in juice, undrained

Lightly grease the inside of a 5- to 6-quart slow cooker crock with butter or nonstick spray to help keep the cake from sticking and make cleanup easier.

Pour the entire can of pineapple tidbits, along with all of the juice, into the bottom of the slow cooker. Spread the fruit out so it covers the bottom in an even layer. The juice will form the base of your clear, bubbling tropical syrup as it cooks.

Sprinkle the dry white cake mix evenly over the pineapple layer. Do not stir. Use your fingers or the back of a spoon to gently level the dry mix so it covers the fruit from edge to edge, like a blanket. Leaving it mostly dry on top is what gives you that crumbly dump cake texture.

Sprinkle the sweetened shredded coconut evenly over the dry cake mix, covering the surface completely. This will toast slightly on top and soak up some of the syrup underneath, giving you that sweet, beachy “ocean water” flavor and look.

Place the lid on the slow cooker. Cook on HIGH for 2 to 2 1/2 hours, or on LOW for 4 hours, until the edges are set and golden, the coconut on top is lightly toasted, and you can see clear, bubbling syrup around the sides. The top will look crumbly and dry in spots, with moist pockets where the syrup has bubbled through.

Once cooked, turn the slow cooker to WARM and let the cake rest, covered, for about 15 minutes. This helps the syrup thicken slightly so you get nice spoonfuls of both cake and juice.

To serve, scoop the warm ocean water dump cake straight from the slow cooker into bowls, making sure to dig down to the bottom to get some of the clear, tropical syrup with each serving. If you like, top with vanilla ice cream or whipped topping and an extra sprinkle of coconut.

To give this cake its signature vibrant blue “ocean water” look, you can very lightly tint the coconut before adding it: place the sweetened shredded coconut in a large zip-top bag, add 2–3 drops of blue food coloring, seal, and massage the bag until the color is streaky and uneven, like waves. Sprinkle this over the cake mix as directed. For a stronger blue, add another drop or two, but go slowly so it still looks natural and beachy rather than neon. If you’d like a more pronounced tropical flavor, you can use pineapple tidbits in pineapple-coconut or tropical blend juice instead of plain pineapple juice, as long as the can size stays close to 20 ounces. For a little extra texture, stir a handful of chopped pecans or macadamia nuts into the coconut before sprinkling it on top (this does add a fourth ingredient, so my uncle only does it when he’s not bragging about the “3-ingredient secret”). If your slow cooker runs hot, start checking at the 2-hour mark on HIGH so the coconut doesn’t scorch; every appliance is a little different. For food safety, always cook the cake until it is piping hot and bubbling in the center, not just around the edges, and keep the lid on while cooking to maintain a safe temperature. Once everyone has eaten, turn the slow cooker off and let the cake cool; refrigerate leftovers within 2 hours in a covered container and enjoy within 3 days. Reheat individual portions gently in the microwave until steaming hot before serving.