Watermelon Slice Cookies
These Watermelon Slice Cookies are an adorable treat that you can use as a baking activity with your kids. They’re bright, cheerful, and taste just as good as they look. It is a great treat for summer parties, birthdays, picnics, or even as a gift.
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This recipe can make 24 cookies, and if you need more than that, you can double the recipe. And since this sweet snack recipe is great for pool parties, maybe you might love to check out my list of pool party snack ideas.
How to Make Watermelon Slice Cookies
Ingredients you’ll need for the cookies
Ingredients you’ll need for the royal icing
Step by Step Guide
1. In your stand mixer, blend the butter, sugar, and egg with the whisk attachment until smooth and creamy. Add the vanilla and mix again.
2. In a separate bowl, mix the flour and salt, then slowly add that into the wet mixture until the dough is nice and smooth.
3. Roll out half of the dough on a floured piece of parchment paper until it’s about ½ inch thick. Use a 3-inch round cookie cutter to make circles, then cut each circle in half to create little watermelon slice shapes.
4. Place them on a parchment-lined baking sheet.
5. Bake at 350°F for 10–12 minutes, or until the edges just start turning golden. Let them cool completely on a wire rack before decorating.
6. In your mixer, whisk together the warm water, meringue powder, and Karo syrup until smooth. Slowly add the powdered sugar (a couple cups at a time), mixing on low speed until everything’s blended and creamy.
7. Now split your icing into four bowls. One gets 2 tsp of watermelon Jello powder + a couple drops of hot pink food coloring. The others get lime green, dark green, and black food coloring—one color per bowl.
8. Decorate the Cookies. On the rounded edge, pipe a thick line of lime green on the outside, then a second line just inside that.
9. Outline the pink part of the “watermelon” and fill it in with the hot pink icing.
10. Between those two green lines, add a skinny strip of dark green. Add little black dots on the pink part and use a cookie scribe or toothpick to drag them down slightly—they’ll look just like seeds!
11. Let the icing set for at least an hour before serving or packaging them up.
Serve and Enjoy!
Important Recipe Notes
- Use softened butter, not melted – You want that perfect cookie texture, and softened (room temp) butter is key for getting it just right.
- Roll the dough evenly – Try to keep the dough around ½ inch thick when rolling. Too thin, and your cookies may get crisp or break when decorating.
- If your dough feels too soft or sticky, pop it in the fridge for 15–20 minutes before rolling and cutting. It’ll be easier to handle!
- Royal icing can be made in advance and stored in an airtight container in the fridge for up to a week. Just give it a good stir before using.
- Use food coloring gel – Gels give you vibrant colors without watering down the icing. A little goes a long way!
- Before decorating, make sure your cookies are fully cooled so the icing doesn’t melt or slide off.
- Royal icing takes about an hour (or more) to fully set. If you’re gifting or packing these up, be sure they’re totally dry to avoid smudges.
- Let the kids help with the pink part and sprinkle on mini chocolate chips as “seeds” if you want a shortcut to the piped version!
Watermelon Slice Cookies
Ingredients
For the Cookies
- 1 cup butter softened
- 1 cup sugar
- 1 egg
- 2 tsp vanilla
- 2 ½ cups flour
- 1 tsp salt
For the Royal Icing
- ¾ cup warm water
- ⅓ cup meringue powder
- 1 ½ tbsp Karo syrup
- Two 16-oz bags of powdered sugar
- 1 small box of watermelon Jello
- Food coloring gel: hot pink, lime green, dark green, black
Instructions
- In your stand mixer, blend the butter, sugar, and egg with the whisk attachment until smooth and creamy. Add the vanilla and mix again.
- In a separate bowl, mix the flour and salt, then slowly add that into the wet mixture until the dough is nice and smooth.
- Roll out half of the dough on a floured piece of parchment paper until it’s about ½ inch thick. Use a 3-inch round cookie cutter to make circles, then cut each circle in half to create little watermelon slice shapes.
- Place them on a parchment-lined baking sheet.
- Bake at 350°F for 10–12 minutes, or until the edges just start turning golden. Let them cool completely on a wire rack before decorating.
- In your mixer, whisk together the warm water, meringue powder, and Karo syrup until smooth. Slowly add the powdered sugar (a couple cups at a time), mixing on low speed until everything’s blended and creamy.
- Now split your icing into four bowls. One gets 2 tsp of watermelon Jello powder + a couple drops of hot pink food coloring. The others get lime green, dark green, and black food coloring—one color per bowl.
- Decorate the Cookies. On the rounded edge, pipe a thick line of lime green on the outside, then a second line just inside that.
- Outline the pink part of the “watermelon” and fill it in with the hot pink icing.
- Between those two green lines, add a skinny strip of dark green. Add little black dots on the pink part and use a cookie scribe or toothpick to drag them down slightly—they’ll look just like seeds!
- Let the icing set for at least an hour before serving or packaging them up.
