Make the cookie dough and wrap it in cling foil. Refrigerate for 30 minutes so it is easier to roll out. At the same time also chill an empty baking tray in the refrigerator.
Preheat the oven to 350F/175C.
Roll out the refrigerated dough between 2 pieces of parchment paper to a ½ cm/¼ inch-thickness. Remove the top piece of parchment paper and use your cookie cutter to cut out gingerbread men. After that use your cut-out surfboards and Santa hats to cut out these shapes out of dough. Remove all the leftover dough (which can be chilled and rolled out again to cut out more cookies).
Transfer parchment paper with the cut-out cookies on it, to the pre-chilled baking tray. Now 'build' your surfing gingerbread men cookies by placing a ginger bread man on an upright surfboard or the other way around; place a short board on top of the middle section of a gingerbread man, like he is carrying his surfboard to the beach. Same for the Santa hats; I place a hat on top of the gingerbread man's head (check the photos in the text above for examples).
Bake the cookies in the preheated oven. Once they are ready, after 18-20 minutes, let them cool off completely before icing them.
Meanwhile whisk together all the icing ingredients; egg whites (or meringue powder), powdered sugar (or xylitol) and lemon juice. Whisk until everything is well combined and some air has been incorporated.
Add color to the royal icing. Start with just 1 drop of gel food coloring and add another drop every time until you have reached the right color. Scoop every color into a resealable bag. Cut off the tip of one of the corners of each bag. Now you are ready to pipe the icing on the cookies.
First draw a line around the area you want to fill in. After that ''flood' it; outline all the cookies first, before you fill them all in (flooding). When using different colors on a cookie, wait until 1 colored area has dried a bit, before using another color.
Once the icing has hardened, the cookies are ready to eat!