My mom served this at our memorial day cookout and people were begging for the secret recipe. 4 ingredients for a magical bubbly vintage masterpiece.

This slow cooker 4-ingredient blackberry grunt is the kind of humble, old-fashioned dessert my mom would pull out at our Memorial Day cookouts, and everyone would suddenly forget about the burgers. It’s a vintage-style recipe where juicy blackberries bubble away into a deep purple compote under a lid of fluffy, steamed dumpling topping. With just four pantry-friendly ingredients and a slow cooker doing the work, it feels almost too simple for how magical and nostalgic it tastes—like something a grandma would have made on a summer evening when berries were overflowing.

Serve the blackberry grunt warm, straight from the slow cooker, spooning the bubbling berries and tender dumplings into bowls. It’s wonderful on its own, but a scoop of vanilla ice cream or a dollop of whipped cream melts into the syrupy berries and makes it extra special. For a cookout, I like to set the slow cooker on “warm” and let everyone serve themselves, with a little bowl of extra fresh blackberries on the side. A cup of coffee or hot tea is lovely with it, but kids usually go for cold milk or lemonade.

Servings: 6-8

2 (16-ounce) bags frozen blackberries (about 6 cups), unthawed

Lightly mist the inside of a 4- to 6-quart slow cooker with nonstick cooking spray to help with cleanup and prevent sticking.

Add the frozen blackberries to the slow cooker. Sprinkle the granulated sugar evenly over the berries, then pour the water over the top. Give everything a gentle stir so the sugar and water are worked down into the berries, but don’t worry if it’s not perfectly mixed.

Cover the slow cooker with the lid and cook the blackberry mixture on HIGH for 1 1/2 to 2 hours, until the berries are soft, juicy, and bubbling around the edges. The liquid should look like a loose, deep purple syrup.

While the berries are finishing their first cook, prepare the dumpling topping. In a medium bowl, add the baking mix. Gradually stir in just enough of the hot blackberry syrup from the slow cooker—about 1/2 cup to 3/4 cup—to create a thick, sticky dough. It should be softer than biscuit dough but firm enough to hold a mound on a spoon. If it gets too stiff, stir in an extra tablespoon or two of hot syrup or water; if it’s too loose, sprinkle in a bit more baking mix.

Once the berry mixture is bubbling, uncover the slow cooker. Working quickly so you don’t lose too much heat, drop spoonfuls of the dumpling dough over the surface of the hot berries, spacing them slightly apart. You should have 8 to 10 rough mounds of dough, covering most of the surface but leaving some gaps for steam to escape.

Place a clean kitchen towel or a double layer of paper towels over the top of the slow cooker, then put the lid back on. The towel will catch excess moisture so the dumplings cook up fluffy instead of soggy. Make sure the towel edges are secured up and away from the heating element.

Cook on HIGH for another 1 1/2 to 2 hours, or until the dumplings are puffed, set, and lightly golden on top. They should feel firm and springy when gently pressed, and a toothpick inserted into the center of a dumpling should come out clean or with just a few moist crumbs (no raw dough).

Turn the slow cooker to WARM and let the grunt sit for about 10 minutes before serving. This lets the syrup thicken slightly while everything is still hot and bubbly. To serve, spoon a dumpling or two into each bowl and ladle plenty of the deep purple blackberry syrup and fruit around it.

If you have fresh blackberries, you can substitute 6 cups fresh for the frozen. Reduce the water slightly to about 3/4 cup, since fresh berries release a bit less liquid at first; check the syrup after the first hour and add a splash more water if it seems too thick or dry. For a slightly less sweet dessert, cut the sugar back to 3/4 cup; for a more old-fashioned, jammy feel, leave it as written. If your family prefers a thicker dumpling, you can make the dough a bit stiffer by adding an extra 1/4 cup baking mix before dropping it on the berries. Picky eaters who aren’t sure about blackberry seeds often do better when the berries are cooked down very soft; you can give the hot berry mixture a light mash with a potato masher before adding the dumplings to break things up. A lemon twist is lovely: if you don’t mind technically adding a fifth ingredient, stir in 1 to 2 teaspoons of grated lemon zest with the berries at the beginning to brighten the flavor. For food safety, always cook the grunt on HIGH as directed so the dumplings reach a safe internal temperature; they should not be doughy in the center. Keep the lid on while cooking except for quick checks, since repeated lifting can drop the temperature and undercook the dough. Once everyone has eaten, cool leftovers promptly and refrigerate within 2 hours; reheat individual portions in the microwave until steaming hot before serving again.