3-Ingredient Lemon Cake

Ingredients 3-Ingredient Lemon Cake

1 box lemon cake mix, approximately 15.25 ounces
1 can lemon pie filling, approximately 21 ounces
3 large eggs

Important: Use the cake mix dry. Do not add the water, oil, or additional eggs listed on the package. This recipe replaces those package additions with lemon pie filling and the three eggs listed above.

Ingredient Notes

Lemon cake mix: A standard lemon cake mix provides the strongest lemon flavor without requiring extra ingredients. Box sizes vary, so choose one close to 15.25 ounces. A substantially smaller or larger box may change the consistency and baking time.

Lemon pie filling: Use a prepared filling intended for lemon pies. It should be thick, smooth, and ready to use. Lemon pudding, lemon juice, and lemon curd are different products and should not be substituted directly in this recipe.

Eggs: Large eggs provide structure and help the cake rise. For easier mixing, remove them from the refrigerator about 20–30 minutes before preparing the batter. Cold eggs will still work if you need to start immediately.

Instructions

Step 1: Preheat the oven.

Preheat your oven to 350°F (175°C). Position a rack in the center so the cake receives even heat. Allow the oven to finish preheating before placing the batter inside. Starting with a properly heated oven helps the cake rise and bake more consistently.

Step 2: Prepare the baking pan.

Line a 9 × 13-inch baking pan with parchment paper, covering the bottom and extending it up two opposite sides. This makes removing the cooled cake easier. A light-colored metal pan is ideal because it generally browns the edges less aggressively than a dark pan.

Step 3: Combine the eggs and filling.

Crack the eggs into a large mixing bowl and whisk until the yolks and whites are combined. Add the lemon pie filling and stir until the mixture looks mostly smooth. Scrape the bottom and sides of the bowl so no streaks of egg remain.

Step 4: Add the cake mix.

Add the dry lemon cake mix to the bowl. Stir gently with a sturdy spatula or use an electric mixer on low speed until the dry ingredients are incorporated. Scrape around the bowl as needed. The batter will be thicker than some traditional cake batters.

Step 5: Avoid overmixing.

Stop mixing once there are no visible pockets of dry cake mix. A few small lumps are fine. Beating the batter excessively can produce a tighter, less tender crumb. You only need a uniform mixture, not a perfectly glossy or completely lump-free batter.

Step 6: Fill the pan.

Transfer the batter to the prepared pan. Use a spatula to spread it evenly into the corners and level the surface. Because the batter is fairly thick, it may not spread evenly by itself. An even layer helps prevent thin edges from overbaking before the center is ready.

Step 7: Bake the cake.

Bake for 30–40 minutes, checking at the earlier end of the range. The surface should look set, and the edges should be lightly golden. Insert a toothpick into the center: it should come out clean or with a few moist crumbs, without wet batter.

Step 8: Cool before slicing.

Place the pan on a heatproof rack and let the cake cool for at least 30 minutes. It will be delicate while hot, so avoid cutting immediately. For neater squares, allow it to cool completely, then slice with a clean knife, wiping the blade between cuts.