Lego Sheet Cake

Ingredients

This recipe is for a Lego cake without fondant, making it perfect for beginners or anyone who, like me, isn’t a big fan of fancy cake decorations 😉. This simple Lego cake is a combination of other recipes, like my lemon sheet cake. The special twist: I use apple juice instead of milk in the batter and also brush it on after baking. This keeps the cake wonderfully moist and fruity! Of course, the real highlight is the decoration: a colorful icing topped with matching chocolate candies.

Now, let’s be honest—a Lego cake is not health food. But you don’t need to use an excessive amount of sugar (650g!) and butter (440g) like some other recipes suggest. What’s your take on that?

How to Make the Lego Cake

Prep the Pan: Grease a baking sheet (at least 16 x 14.5 inches / 42 x 37 cm) and dust with flour, or line it with parchment paper. Preheat your oven to 350°F (175°C).

Recipe Recommendation

Rainbow Sheet Cake

This sheet cake gets really fluffy and is an eye-catcher at any party! Kids aren't the only ones to love this colorful rainbow sheet cake or parrot cake.

Check out this recipe!

Make the Batter: Beat the softened butter and sugar together for several minutes until creamy and light. Gradually add the room-temperature eggs, one at a time, until fully incorporated.

Mix Dry Ingredients: In a separate bowl, mix the flour, cornstarch, baking powder, salt, and lemon zest. Gradually add this mixture to the egg and butter mixture, alternating with the apple juice (but be careful not to overmix). The batter should be thick enough to hold its shape on a spoon; add a bit more liquid if needed.

Bake the Cake: Spread the batter evenly onto the prepared baking sheet and smooth the top. Bake for about 20 minutes. Use a toothpick to check for doneness—the cake should remain light in color and not be overbaked, so it stays moist.

Cool and Slice: Lightly brush the warm cake with some apple juice and let it cool completely. Once cooled, slice the cake into 4-6 strips, depending on how many colors you want to use.

Make the Frosting: Sift the powdered sugar into a bowl and mix with enough juice and milk to create a thick but spreadable frosting. Divide the frosting into 4-6 portions and color each with natural food coloring. Start with a small amount (about ¼ teaspoon) of sifted color powder, adding more until you get the desired shade.

Decorate: Use a small cake spatula, pastry scraper, or spoon to spread the frosting evenly over the cake strips. Then, cut the strips into oblong or square pieces and top each piece with chocolate candies to mimic Lego bricks.

Top Tip

You don’t need artificial food coloring full of chemicals to create this vibrant Lego cake. Natural food powders from fruits and vegetables, as well as gel or paste colors (make sure they're fat-soluble if using with white chocolate), work beautifully.

Recipe Card

Print Recipe Click on the stars to rate the recipe

5 from 1 vote

Lego Cake

Super easy, colorful building block cake from the baking sheet. You can easily adapt this cake, and the decoration can be made without synthetic food coloring.

Prep Time30 minutes mins

Baking Time20 minutes mins

Servings: 20

Calories: 278kcal

Equipment

• 1 Baking Sheet

Ingredients

1x2x3x

For the dough

• 250 grams (1 cup) butter, soft
• 180 grams (1 cup) sugar
• 6 eggs, medium
• 300 grams (2 ½ cups) all-purpose flour
• 130 grams (1 cups) cornstarch
• 1 small bag baking powder
• 1 pinch salt
• 1 teaspoon grated lemon zest, quantity to taste
• 150 milliliters (10 tablespoons) apple juice, or milk

For the decoration

• 3 tablespoons apple juice, for coating/soaking
• 250 grams (2 cups) powdered sugar
• 3 tablespoons milk, very coarse
• 3 tablespoons apple juice, or lemon juice
• 200 grams (1 cups) colored chocolate lentils
• 4 teaspoons natural food coloring

Instructions

• Grease a baking sheet (at least 1614,5 in / 4237 cm) and dust with flour or cover with baking paper. Preheat to 350°F/175°C.
• Beat the softened butter and sugar for a few minutes until creamy or light and fluffy. Gradually beat in the room-warm eggs until well blended.
• Mix flour, cornstarch, baking powder, salt, and lemon zest. Stir into the egg cream alternately with the apple juice (but not too long). The dough should be hard to tear from the spoon; otherwise, use more liquid if necessary.
• Spread dough evenly on a baking sheet and smooth out. Bake for about 20 minutes. Test with chopsticks. The cake should remain light in color and not stay in the oven too long to avoid dryness.
• Brush the cake very thinly with some juice and let cool completely. Then cut into 4-6 strips (depending on the number of colors you want).
• For frosting, sift powdered sugar and mix with enough juice and milk to make a thick but still spreadable frosting. Divide frosting into 4-6 portions. Thoroughly stir a small amount (e.g., ¼ teaspoon) of sifted coloring powder into each frosting portion first. Add more powder as desired until desired shade is achieved.
• Using a small cake palette, pastry scraper, or spoon, spread divided dough evenly thinly with one color, cut into oblong or square pieces with a large sharp knife, and top Lego-style with chocolate lentils.

Notes

Adjust the amount of powdered sugar to control the thickness of the icing. Using milk in the frosting enhances the opacity and vibrancy of the colors. Natural food coloring powders work well for a healthier option, while gel or paste colors may require slight adjustments based on the instructions.

 

Ingredient substitutions

Do you want to replace some ingredients? Here you find tips for baking ingredient substitutions!

Variations

If you want to make kids smile, bake this Lego sheet cake soon! You can also use the colors right away for a rainbow cheesecake or healthy donuts 🙂. I have plenty more delicious sheet cakes and fun baking recipes for kids!