Here are the ingredients that you will need in order to make homemade sweet tarts:
- 1/4 c. clear soda (Lemon-Lime! Sprite! 7-up! Squirt!)
- 3/4 teaspoon powdered gelatin
- 3 ½ cups powdered sugar, plus more for rolling
- 4 teaspoons Emergen-c (any flavor you want) or 2 teaspoons citric acid
- Extracts
- Food coloring

Source: veganfoodlover.com
Here are the directions you need to follow in order to make homemade sweet tarts:
First, in a small microwaveable bowl, you need to combine the gelatin and the soda. After about 5 minutes, microwave the mixture on high for about 30 seconds, or until the gelatin dissolves completely and you can’t see any granules. The mixture should have a smooth consistency.
Next, in a medium-sized bowl, mix in ½ cup of powdered sugar and all of the emergen-c. Stir gently to combine the ingredients until they are fully mixed together.
Then, add in the remaining powdered sugar to the bowl and mix with a spatula until the mixture is smooth and somewhat sticky to the touch. Try not to overmix the batter or it will become tough and hard to work with.
Next, turn the dough out onto a work surface covered with some extra powdered sugar to prevent the dough from sticking too much. Then. knead the mixture until the dough is much less sticky and can be easily flattened with a rolling pin.
Next, you want to separate the dough into as many different flavors and colors you want. Stir in your choice of flavorings and colorings to each bowl.
Then, roll each dough out to ¼” thick. Cut out as many tiny circles or other shapes you like and transfer to a baking sheet to dry out.
Drying can cake between 12-48 hours, be patient! If you have a room with a dehumidifier or a food dehydrator, that will greatly speed up the process. Then eat and enjoy!

Source: instructables.com