Line two large baking sheets with parchment paper and preheat oven to 350℉.
In the microwave safe medium bowl, microwave 1/2 cup of dairy-free dark chocolate chips for 30 second increments until melted. Set aside and let cool until close to room temperature.
In the other medium bowl, whisk together flour, baking powder, and baking soda until the baking powder and baking soda are evenly distributed. Set aside.
In the large bowl, combine white sugar, softened vegan butter, vanilla extract and salt. Whisk together until butter and sugar become light and fluffy. Then, mix in the egg until combined.
Once cooled, add the melted dark chocolate to the wet ingredients and mix until combined.
Add the dry ingredients to the wet ingredients and mix until thoroughly combined. Fold in the remaining chocolate chips from the bag.
Pour sprinkles into a small bowl. Gently roll 1-2 tablespoons of cookie dough into a ball and roll half the ball in the rainbow sprinkles. Place onto lined baking sheet with the non-sprinkle side facing down. Repeat with remaining batter, placing the balls of dough 2-3 inches apart.
Bake at 350℉ for 7-8 minutes until the cookies spread and the middle looks cooked. (Do not bake for longer than 10 minute because the sprinkles will burn)