Steps
1. Preheat oven to 350°F (175°C).
2. Cream the butter and sugar together until light and fluffy.
3. Mix in vanilla extract.
4. In a separate bowl, combine flour and baking powder.
5. Gradually add the dry ingredients to the wet mixture and stir until a dough forms.
6. Add a few drops of yellow food coloring and knead until the dough is evenly colored.
7. Roll out dough on a floured surface to about 1/4 inch thickness.
8. Cut into square shapes to mimic SpongeBob's square body.
9. Place on a baking sheet lined with parchment paper.
10. Bake for 8-10 minutes or until edges are lightly golden.
11. Let cookies cool completely.
12. Prepare royal icing and divide into portions; color them white, black, red, and blue.
13. Use the icing to decorate SpongeBob's eyes, nose, mouth, teeth, and clothes.
14. Allow icing to set before serving.