For the emoji and traditional sprinkles, you'll use royal icing for the base.
Start mixing meringue powder with powdered sugar in a bowl.
Slowly pour water over the ingredients and mix at medium speed. Keep mixing until you get a sticky consistency, like liquid white glue.
Separate the icing into small bowls to add the gel coloring.
I used four different colors, so I had four separate small bowls. Distribute your royal icing accordingly.
Add a few drops of gel food coloring and mix each portion using a clean spoon. Cover the colors you won't use immediately with plastic wrap to protect them.
Pour tiny yellow circles on a baking tray lined with parchment paper for the emoji sprinkles. Fix the shapes using a toothpick and top with two heart-shaped sprinkles for the eyes.
Meanwhile, to make conventional sprinkles pour straight lines and dots on another baking tray lined with parchment paper.
When the emojis are more solid, draw a smile with black icing.