This Watermelon Lemonade Cake is the kind of dessert that makes you smile before you even take a bite. Light, fluffy lemon-scented sponge layers sandwich a vibrant watermelon filling and creamy frosting with a blush-pink glaze that glistens like a summer sunrise. Topped with juicy watermelon cubes and flecks of zest, it’s refreshing, sweet, and undeniably beautiful. Perfect for garden parties, birthdays, or anytime you want to taste sunshine in cake form.
Ingredients
For the Lemon Sponge Cake
2½ cups (312g) all-purpose flour
2 tsp baking powder
½ tsp baking soda
½ tsp salt
1 cup (226g) unsalted butter, softened
1¾ cups (350g) granulated sugar
4 large eggs
Zest of 2 lemons
1 tbsp lemon juice
1 tsp vanilla extract
1 cup (240ml) whole milk
For the Watermelon Filling
1½ cups fresh watermelon, pureed and strained
2 tbsp cornstarch
2 tbsp sugar (adjust depending on watermelon sweetness)
1 tsp lemon juice
For the Lemon Cream Frosting
1 cup (240ml) cold heavy cream
1 (8 oz) package cream cheese, softened
½ cup powdered sugar
1 tbsp lemon zest
For the Pink Glaze
1½ cups powdered sugar
2–3 tbsp watermelon juice or milk
A few drops natural red food coloring (optional)
Instructions
- Make the Cake
Preheat your oven to 350°F (175°C) and grease two 9-inch round cake pans.
Whisk together flour, baking powder, baking soda, and salt.
In a separate bowl, cream butter and sugar until fluffy. Add eggs one at a time, then beat in lemon zest, juice, and vanilla.
Alternate adding flour mixture and milk, beginning and ending with flour. Mix just until combined.
Divide batter between pans and bake 25–28 minutes or until golden and a toothpick comes out clean. Cool completely. - Prepare the Watermelon Filling
In a saucepan, combine watermelon juice, cornstarch, sugar, and lemon juice. Cook over medium heat, stirring constantly, until thickened (about 3–4 minutes). Let cool completely. - Make the Frosting
Whip cream cheese and powdered sugar until smooth. Add lemon zest. In a separate bowl, whip cream to stiff peaks, then fold into the cream cheese mixture. - Make the Glaze
In a small bowl, whisk powdered sugar with watermelon juice or milk until smooth and pourable. Add color if desired for a pink tone. - Assemble the Cake
Place one layer of cake on your plate. Spread a layer of lemon cream frosting, then spoon over watermelon filling.
Top with the second cake layer and coat the whole cake with the remaining lemon cream.
Pour glaze gently over the top, letting it drip slightly down the sides for that dewy effect.
Decoration Tips
Top each slice with small, neat cubes of fresh watermelon. To keep them looking crisp, blot the cubes dry before placing them.
Grate a touch of lemon zest over the glaze to bring contrast and a fresh citrus burst.
If you’re serving outside, keep watermelon cubes in the fridge until the last minute so they stay chilled and don’t release too much juice.
Optional: Add a few fresh mint leaves around the watermelon cubes for a cooling pop of green.
