Directions:

1. In large bowl of a stand mixer combine the butter and sugar. Beat with a paddle until light and fluffy.
2. Gradually add the egg, milk, and vanilla extract. Add flour, baking soda and salt. Mix until just combined.
3. Place the dough on a floured work surface. Use a rolling pin to roll the dough to a ¼ inch thickness.
4. Cut out cookies with a rainbow shaped cookie cutter and place on to a cookie sheet.
5. Place the cookies in the refrigerator for at least 30 minutes before baking.
6. Bake the cookies at 375°F for 10-12 minutes. Allow to cool at least 30 minutes to 1 hour before decorating.
7. To make the icing: Whip the egg white until it is frothy-- about 3-4 minutes. Add 4 tablespoons of milk and the lemon extract.
8. Slowly add the powdered sugar and salt. Whip for an additional 4-5 minutes until the icing is shiny and smooth. Adjust the thickness with the remaining milk if the consistency is too thick.
9. Separate the icing into 7 bowls. Use the gel food coloring to color each bowl individually leaving one bowl white.
10. Place each colored icing in a piping bag fitted with a small round tip.
11. Make the rainbow stripes with the prepared icing. Allow to set for 10-15 minutes.
12. Pipe the white icing on the sides to make clouds and top with mini marshmallows. Enjoy!