Combine the cake mix, eggs and egg yolk, milk, and melted butter in a large mixing bowl, whisking until well blended. Portion the batter into the prepared doughnut pan.
Bake for 12 minutes or until baked through and the toothpick test returns clean. Repeat with the remaining batter if you are working with one pan at a time.
Melt the almond bark in a microwave-safe bowl in the microwave at 50% power. Heat in 30-second intervals, stirring in between each interval until the chocolate is smooth. Dip each donut into the chocolate and sprinkle immediately with spinkles.