Bake the cake as directed on the box, using a 9-by-13-inch cake pan. Let cool completely. Once the cake is cooled, get organized and set aside plenty of time (at least an hour) to crumble, roll, and dip 4 dozen cake balls.
Crumble the cooled cake into a large mixing bowl. The texture of the cake causes it to crumble easily. Just cut a baked 9-by-13-inch cake into 4 equal sections. Remove a section from the pan, break it in half, and rub the two pieces together over a large bowl, making sure to crumble any large pieces that fall off. You can also use a fork to break any larger pieces of cake apart. Repeat with each section until the entire cake is crumbled into a fine texture. If you have large pieces mixed in, the cake balls may turn out lumpy and bumpy. You should not see any large pieces of cake.
Add three-quarters of the container of frosting. (You will not need the remaining frosting.) Mix it into the crumbled cake, using the back of a large metal spoon, until thoroughly combined. If you use the entire container, the cake balls will be too moist. The mixture should be moist enough to roll into 1.5-inch balls that still hold a round shape. After rolling the cake balls by hand, place them on a wax paper–covered baking sheet. Cover with plastic wrap and chill for several hours in the refrigerator, or place in the freezer for about 15 minutes. You want the balls to be firm but not frozen. If you’re making a project that calls for uncoated cake balls, stop here and proceed to decorate the cake balls, following the project instructions.
Place the candy coating in a deep, microwave-safe plastic bowl. These bowls make it easier to cover the cake balls completely with candy coating while holding the bowl without burning your fingers. (I usually work with about 16 ounces of coating at a time.) Melt the candy coating, following the instructions on the package. Microwave on medium power for 30 seconds at a time, stirring with a spoon in between. You can also use a double boiler to melt the chocolate. Either way, make sure you do not overheat the candy coating.
Now you’re ready to coat. Take a few cake balls at a time out of the refrigerator or freezer to work with. If they’re in the freezer, transfer the rest of the balls to the refrigerator at this point, so they stay firm but do not freeze. Place one ball at a time into the bowl of candy coating. Spoon extra coating over any uncoated areas of the cake ball to make sure it is completely covered in candy coating. Then lift out the cake ball with your spoon. Avoid stirring it in the coating, because cake crumbs can fall off into the coating.
Holding the spoon over the bowl, tap the handle of the spoon several times on the edge of the bowl until the excess coating falls off and back into the bowl. This technique also creates a smooth surface on the outside of the cake ball. Transfer the coated cake ball to another wax paper–covered baking sheet to dry. Let the coated cake ball slide right off the spoon. Some coating may pool around the base of the ball onto the wax paper. If so, simply take a toothpick and use it to draw a line around the base of the cake ball before the coating sets. Once the coating sets, you can break off any unwanted coating. Repeat with the remaining cake balls and let dry completely. If you have extra candy coating left over, pour it into a resealable plastic bag (and then snip off the corner) or into a squeeze bottle and drizzle it over the tops in a zigzag motion to decorate. You can make the cake balls ahead of time and store them in an airtight container on the counter or in the refrigerator for several days.
<b>Tips:<b> The cake balls will be easier to roll if you wash and dry your hands periodically during the rolling process. Dry your hands completely each time, and make sure you don’t get water in the candy coating, as it can make it unusable. You can use a mini ice cream scoop to get uniform-size cake balls. If you don’t need or want to make 48 cake balls, simply divide the cake in half for 24 cake balls or in quarters for 12 and freeze the remaining cake for later use. Remember to reduce the amount of frosting proportionally.