Prepare cake batter according to package directions. Beat cake mix with eggs, water, and vegetable oil in a large mixing bowl as specified on the box.
Pour batter into a greased 9×13-inch baking dish or two 8-inch round cake pans. Bake in a preheated 350°F oven until a toothpick inserted into the center comes out clean, about 25 minutes. Let cake cool completely.
Once cooled, crumble the entire cake into fine crumbs using your hands or a fork in a large bowl. Remove any dark edges or overly crispy pieces.
Add ⅓ cup frosting to the crumbled cake. Mix thoroughly with a hand mixer, stand mixer, or spoon until combined into a dough-like consistency that sticks together when pressed.
Cover bowl with plastic wrap and freeze for 30-45 minutes until mixture is chilled and easier to work with.
Use a cookie scoop and your hands to roll the mixture into evenly sized balls about the size of ping pong balls. Place on a parchment-lined baking sheet, ensuring they don't touch.
Freeze again for 30 minutes or until balls are completely hard. This second freeze is crucial for preventing cracking and crumbling.
Melt candy melts in the microwave in 30-second intervals, stirring between each burst, until completely smooth. Use separate bowls for pink and white candy melts.
Remove frozen cake balls from freezer. Dip the tip of a lollipop stick about ½ inch into melted candy, then immediately insert into a cake ball, pushing halfway through. Repeat with all balls.
Place cake pops back in freezer for 10-15 minutes until the candy at the base solidifies completely.
Holding the stick, gently dip each cake pop straight down into melted candy coating. Rotate to coat all sides, then lift and tap the stick lightly against the bowl edge to remove excess coating.
While coating is still wet, immediately add heart sprinkles or decorations. Place cake pops upright in a styrofoam block or cake pop stand.
Let coating set at room temperature for 15 minutes until completely hardened. Your Valentine's Day Cake Pops are ready to serve or gift!