These 3-ingredient lemon bars are the kind of bright, gooey dessert that shows up at every spring cookout in my family. My aunt started bringing them years ago because she needed something she could throw together after work, and they quickly became the pan everyone hovered around. The base is soft and cake-like, the lemon layer is sticky and tangy, and a dusting of powdered sugar makes them look a lot fancier than the effort involved. If you’re juggling a busy schedule but still want a homemade dessert, this is the easiest bake you’ll ever pull off.
Serve these lemon bars chilled or at room temperature on a simple white plate so the bright yellow filling really pops. They’re perfect next to grilled burgers, brats, or chicken at a cookout, and they balance out heavier picnic sides like potato salad or baked beans. I like to cut them into small squares so people can grab one alongside fresh berries or a scoop of vanilla ice cream. A cup of hot coffee, iced tea, or lemonade also pairs really well with the sweet-tart flavor.
3-Ingredient Lemon Bars
Servings: 16 squares

Ingredients
1 box (15.25 oz) yellow cake mix
1 can (21 oz) lemon pie filling
1/3 cup powdered sugar, plus more for dusting
Directions
Preheat your oven to 350°F (175°C). Lightly grease an 8x8-inch or 9x9-inch baking pan, or line it with parchment paper, leaving some overhang to lift the bars out later.
In a medium mixing bowl, add the dry yellow cake mix and 1/3 cup powdered sugar. Stir with a spoon or spatula until the powdered sugar is evenly distributed throughout the cake mix.
Measure out about 1 cup of the dry mix and set it aside in a small bowl for the topping.
Pour the remaining dry mixture into the prepared pan. Press it firmly and evenly into the bottom using clean hands or the back of a measuring cup to form a soft, even crust.
Open the can of lemon pie filling and spread it gently over the crust layer, all the way to the edges. Use a spatula to smooth it into an even, gooey layer.
Sprinkle the reserved 1 cup of cake mix mixture evenly over the lemon filling. It won’t fully cover the lemon layer; you’re aiming for a light, crumbly top that lets some of the filling peek through.
Bake in the preheated oven for 28–34 minutes, or until the edges are lightly golden and the top looks set but still slightly soft in the center. The lemon layer will bubble around the edges.
Remove the pan from the oven and let the bars cool completely in the pan on a wire rack. The filling will firm up as it cools, so resist cutting too early or they’ll be extra messy.
Once cooled, dust the top generously with additional powdered sugar. Use a sharp knife to cut into 16 squares, wiping the knife clean between cuts for neater edges.
Serve the lemon bars slightly chilled or at room temperature. Store leftovers covered in the refrigerator for up to 4 days.
Variations & Tips
To make these bars a little lighter, you can use a sugar-free yellow cake mix and a reduced-sugar lemon pie filling, but note that the texture may be slightly less gooey. For extra lemon punch, stir 1–2 teaspoons of finely grated lemon zest into the pie filling before spreading it over the crust. If you prefer a slightly firmer base, add 2–3 tablespoons of melted butter to the crust mixture before pressing it into the pan; this will give it a richer, more cookie-like texture. You can also swap yellow cake mix for white cake mix if that’s what you have on hand—the bars will be a bit paler but still delicious. For easy serving at busy cookouts, cut the bars small and use mini cupcake liners to keep fingers from getting too sticky. Food safety tips: Always check that your canned lemon pie filling is not expired and the can is not dented, bulging, or rusted. Let the bars cool on the counter no more than 1–2 hours, then refrigerate promptly and keep them chilled if serving outdoors on a hot day; discard any bars that have been sitting out in the heat for more than 2 hours. Wash your hands before and after handling the baked bars, especially if you’re cutting and serving them directly from the pan at a gathering.