My sister begged me to make these sweet spring packets for our weekend brunch. Just 4 ingredients and you have the most colorful gooey surprise wrapped up in foil.

These slow cooker 4-ingredient foil wrapped confetti cakes started as a last-minute idea for my sister’s spring brunch. She wanted something fun and colorful, but I needed it to be hands-off while I tackled everything else. The solution: little packets of gooey, sprinkle-studded cake batter wrapped in foil and tucked into the slow cooker. They steam up into super soft, gooey mini cakes with a surprise pop of color in every bite, and the best part is you only need a box of mix, some soda, sprinkles, and powdered sugar.

Serve these confetti cakes warm, right out of the foil packets, with a light dusting of extra powdered sugar. They’re perfect on a brunch table next to a big bowl of fresh berries, a simple fruit salad, or a platter of scrambled eggs and bacon to balance the sweetness. For something a little fancier, add a dollop of whipped cream or a scoop of vanilla yogurt on the side. Coffee, mimosas, or even a cold glass of milk all pair really well with the soft, gooey texture and sweet, vanilla-citrus flavor.

Servings: 8

1 (15.25 oz) box white or yellow cake mix

Line your slow cooker with a single layer of foil packets in mind: clear some counter space and tear 8 pieces of aluminum foil, each about 8x8 inches. Lightly mist the center of each piece with nonstick spray if you have it, to help prevent sticking.

In a medium mixing bowl, add the dry cake mix and powdered sugar. Whisk together until the powdered sugar is fully dispersed and there are no visible lumps. This sweetens and helps the cakes set up a little more firmly while still staying gooey.

Pour the lemon-lime soda into the dry mixture. Gently stir with a spatula or wooden spoon just until the batter is smooth and no dry pockets remain. The batter will be slightly thinner than traditional cake batter but still spoonable.

Fold in the rainbow sprinkles, stirring just enough to distribute them without overmixing. Overmixing can cause the colors to bleed too much into the batter, so a few gentle turns is all you need for that confetti look.

Spoon the batter into the center of each foil square, dividing it as evenly as you can among the 8 pieces. Aim for about 1/4 to 1/3 cup of batter per packet, leaving plenty of foil around the edges so you can seal them without the batter leaking out.

Bring the sides of each foil square up and over the batter and fold the edges together to seal, creating a loose but fully closed packet. Make sure there are no big gaps in the seams so steam stays inside and the batter doesn’t escape as it cooks.

Arrange the foil packets in a single, snug layer in the bottom of the slow cooker. It’s okay if they touch and are packed tightly; that helps them stay upright. If your slow cooker is deep, you can gently stack a second layer on top, offsetting the seams.

Cover the slow cooker with its lid, set to LOW, and cook for 2 to 2 1/2 hours, or until the cakes feel set when you gently press the tops through the foil. They should feel springy but still soft and a little gooey in the center—almost like a very moist cupcake.

Turn off the slow cooker and carefully lift out the foil packets with tongs or a spatula. Let them sit for about 5 to 10 minutes to cool slightly; the steam inside will be very hot when first opened.

Open each foil packet carefully, folding the sides down to create a little foil “plate” around the cake. Dust the tops generously with additional powdered sugar just before serving for that pretty, snowy finish and a touch of extra sweetness.

Serve the confetti cakes warm, straight from their foil wrappers. Any leftovers can be cooled completely, rewrapped, and stored in an airtight container at room temperature for up to 2 days. Rewarm in the slow cooker on LOW or in a low oven, still in their foil, until just warmed through.

Try swapping the lemon-lime soda for cream soda or orange soda to change up the flavor while keeping the 4-ingredient formula. Use a funfetti cake mix instead of white or yellow for even more color (you can reduce the added sprinkles to 2 tablespoons if the mix already has some). For a slightly richer texture, use a French vanilla or butter cake mix. If you want more color on top, sprinkle a pinch of extra rainbow sprinkles over the cakes right after opening the packets, then dust with powdered sugar so the colors peek through. For mini portions at a kids’ party, make 10–12 smaller packets and shorten the cook time slightly, checking around 1 1/2 hours. To prep ahead, you can mix the dry cake mix and powdered sugar the night before and pre-cut your foil squares; in the morning, just add soda and sprinkles, assemble the packets, and let the slow cooker do the work while you handle the rest of brunch.