Simple Birthday Watermelon Cookies

We can all agree watermelon colors and flavor evoke the spirit of summertime joy. And whether you’re hosting a summer party or celebrating a special day, these decorated birthday watermelon cookies are sure to make people smiles.

Cupcake, candle, present, party hat and a round cookie decorated with watermelon designs, using royal icing.

updated from 2012


In this tutorial I guide you thru the process of making 4 different cookie designs. Let’s dive in.

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Sugar cookies decorated like watermelon displayed flat on a work surface.


  • Cookie Cutters: I used party hat, present, candle, cupcake and a round
  • Tipless Piping Bag
  • Airbrush
  • Food Colors for Airbrushing: bright green, or use leaf green and yellow
  • Edible Gold Luster Dust or Edible Gold Paint
  • Paintbrush
  • Scribe
  • Stencil Holder or Magnets
  • Stripe Stencil – how to make your own at home
  • Gel Food Colors: red or pink, green, black
  • Gold Sanding Sugar
  • Funnel Tray
  • Foodoodlers Edible Marker-brown
  • Rainbow Dust Black Edible Marker- use fine tip end
  • Food Wrap
  • Piping tip #150 (narrow petal tip) to pipe ruffled edge, or use petal tip #103 or #104

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In this cookie decorating tutorial I used a present, party hat, candle, cupcake and round cookie cutter (not shown in the image below). Plastic cutters are from a set by Sweet Sugarbelle. If you can’t find it use similar cutters instead.

Present, party hat, candle and a cupcake cookie cutters.


Next step is to bake the cut-out cookies and prepare royal icing.


  • Red or Pinkish Red – 15 second consistency
  • White – 15 second consistency, and stiff
  • Light Green – 20 second consistency, piping consistency, and stiff
  • Dark Green – 20 second consistency
  • Mustard yellow, golden yellow or light brown – 25 second consistency
  • Black – 20 second consistency
Undecorated cookies and piping bags with colored royal icing.


Make a cardstock scalloped edge template and trace it onto a cookie with an edible marker. Draw the decorated guides on the cookie (steps 1-3).

Hand-holding an edible marker, drawing guides onto a cookie.

Outline and flood the liner sections with 15-second consistency white royal icing. Use a scribe to smooth the icing and let it dry for 6-8 hours (steps 1-6).

Cupcake-shaped cookies with white royal icing liner.


I wanted to airbrush cookies with bright green color, so I used a drop of leaf green and 3-4 dots of lemon airbrush food coloring. Cover the needle opening and hold the trigger for 3-4 seconds to mix the colors (steps 1-3).

Hand holding an airbrush gun, pouring airbrush food color into the feeding cup.

You can use a stripe stencil and airbrush to create gingham pattern on a cupcake liner. If you don’t own an airbrush you can either paint the design with an edible paint (gel paint mixed with little bit of clear alcohol) or use a color mist spray instead.

Secure the stencil into a stencil holder or use magnets to keep the stencil from shifting. With the airbrush gun perpendicular to the cookie, airbrush across each open line. It’s feasible to avoid under spray by doing several light coats instead of one heavy coat. If you see stripes moving up and down use a scribe tool to hold them down gently. Lift the stencil (steps 1-4). Place the stencil perpendicular to the first set of lines and airbrush across it again, remove the stencil to reveal beautiful gingham pattern (steps 5-6).

Stripe stencil on top of a cookie. Hand holding an airbrush gun, airbrushing white icing with green airbrush color.
Three cupcake cookies with airbrushed green gingham liners.

Now, let’s move on and decorate the cupcake swirl. Ice the section just above the liner with white icing. And right after, outline and flood the middle of the swirl with 15-second consistency red icing. Let the icing crust for 20 minutes and then continue with two remaining sections, at the top and the bottom (steps 6-8). Let the icing crust well (about 1-2 hours) and continue with the last step.

Decorating the top of the cupcake with red icing.

Finish watermelon cupcake cookie with a green outline (piping consistency) and pipe short black (20 second) lines onto the swirl to make black seeds.

Piping outline onto the cupcake liner and black seeds onto red swirl section.
Cupcake watermelon cookies decorated with red, white, green and black royal icing.


Decorated birthday watermelon cookies wouldn’t be complete without party hat cookies. Outline and flood the triangular part of the cookie with 15-second consistency red icing. Let the icing crust well for 2-3 hours (steps 1-5).

Flooding a cookie with red icing.


First, you need to prepare royal icing pouch. Pipe stiff green icing onto a sheet of food wrap. Next to it pipe stiff white icing, about 1/4 less than green icing. Close the pouch, tie one end (steps 1-3). Trim the other end (step 4). Fit a piping bag with a petal tip #150. Place the pouch, cut side down into a piping bag (steps 5-6). Then squeeze the piping bag until both of the colors come out of the piping tip (steps 7-8).

Stiff white and green royal icing in a food wrap pouch.

Hold the piping bag so the green icing when it comes out is facing the outer bottom edge of the party hat cookie. Hold the piping bag at about 45 degree, squeeze the piping bag, and move the piping tip up and down as you move across the bottom of the cookie (steps 1-3).

Piping a green-white ruffle onto a cookie.

Pipe black seeds onto the red section with 20 second black icing. First pipe a large dot and then slowly move the piping bag to form a tear drop (steps 1-3). Immediately, pipe white icing on the edge on every seed to create a highlight (steps 4-6).

Piping watermelon seeds with black icing.

Lastly, decorate the star at the top. Outline and flood the star shape with golden yellow, mustard-colored or light brown icing and dust it with gold sanding sugar (steps 1-8).

Dipping freshly icing cookie into gold sanding sugar.
Party hat cookies decorated with royal icing to look like watermelons.


Inspired by watermelon print wrapping paper I designed watermelon present cookies. To create watermelon pattern, I use wet-on-wet royal icing decorating technique, using 15-second consistency icing. To avoid icing overflowing the cookie, I piped large watermelon outlines and I flooded the cookie with white icing (steps 1-3). Then I filled each section with red icing (steps 4-5), and after I piped a green line leaving a small white gap between the red and green (step 6). Lastly, pipe black seeds with black icing – 20 second consistency (steps 7-8). Let the icing dry.

Piping wet on wet watermelon shapes onto white royal icing.

To enhance the watermelon slices you can use a fine-tip edible marker and draw the outline around each watermelon slice (steps 1-2).

Hand holding a fine-tip edible marker, drawing outlines around wet-on-wet royal icing watermelons.


Using 25 – second consistency golden yellow, brown or mustard colored icing outline and fill the loop. Use a scribe to smooth the icing. Repeat on the other side and let icing crust for 10 minutes (steps 1-4). Make the ribbon bow tails, wait for the first tail to crust for 5 minutes before piping the second one, next to it (steps 5-8).

Piping a royal icing bow onto a present cookie.

Finish the bow with a knot in the middle (steps 1-3), let icing dry.

Piping a knot onto a royal icing bow.

Prepare an edible gold paint: into a paint palette pour edible gold luster dust, pour in a small amount of grain alcohol (Everclear), mix it with a small paintbrush (steps 1-3). Paint the dry bow with gold paint (steps 4-8).

Paintbrush painting a royal icing bow with gold edible paint.
Cookies in a shape of a present decorated with a watermelon pattern and gold luster dust.


First, I created watermelon skin design using two shades of green. Pipe narrow strips of dark green and light green. Don’t wait for the icing to crust, use a scribe tool to lightly blend the edges (steps 1-8). Let icing crust for an hour.

Icing a candle cookie with bright and dark green icing.

Make the wick – pipe a black line with 20-second icing. Pipe a flame with 25 second consistency golden yellow icing (steps 1-4). And lastly, pipe the drips with 20-second consistency green icing (steps 5-8). Let the icing dry.

Piping a flame onto a candle cookie with mustard-colored icing.

Paint the flame with edible gold luster dust (steps 1-3).

Painting icing with gold edible paint.
Decorated candle cookies with a watermelon skin green pattern.


Did you make these Decorated Cookies? Tag @hanielas on Instagram and hashtag it #hanielas


Sugar cookies of different shapes decorated with watermelon royal icing colors.

This decorating tutorial was published on June 29, 2012. On July 26, 2023 I updated this tutorial with new step by step instructions, and step by step photos.

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