Instructions:

1. Melt the chocolate in 30 second intervals in the microwave or over very low heat on the stovetop. Set aside.  
   
2. In the bowl of a stand mixer, combine the butter and sugar. Beat for 1 minute until smooth.  
   
3. Add the egg yolk, melted chocolate, and vanilla extract. Mix until well-combined.  
   
4. In a separate bowl, mix the flour, baking soda, and salt together. Add into the chocolate mixture and mix just until combined.  
   
5. Cover with saran wrap and chill the cookie dough for at least 1 hour.  
   
6. Preheat oven to 350F. Line a large baking pan with parchment paper.  
   
7. Add the sprinkles into a small bowl.  
   
8. Using 2-3 tablespoons cookie dough each, roll into a ball. Toss the cookie ball in the sprinkles bowl to coat in the sprinkles. Place on the prepared baking pan.  
   
9. Repeat with remaining cookie dough, leaving 2” inches of space between the cookies on the baking pan.  
   
10. Press small chunks of chocolate onto the top of each cookie for adding chocolate-y goodness and decoration!  
    
11. Bake for 9-12 minutes, until set in the center. Let cool on the pan for 5 minutes before transferring to a baking rack to cool completely. Enjoy!