Preheat the oven to 350°F and grease a 9"x13" baking dish.
In a large mixing bowl, add the cake mix, milk, oil, and sour cream. Mix until well combined. Pour into the prepared baking dish. Bake for 18-22 minutes, until a toothpick inserted into the center comes out clean or with only crumbs, no raw batter.
Once the cake is out of the oven and still hot (the steam will help stick the mixture together), carefully spoon it into a large mixing bowl or the bowl of a stand mixer fitted with the paddle attachment. Beat with a hand mixer or the stand mixer until a cake pop dough is formed.
Scoop out 16 balls of dough that are ~1.5 tbsp each and roll them into balls. Place on a wax or parchment paper-lined baking sheet. Freeze for about 1 hour. Wrap up the remaining dough and place in the fridge for later.
Using a double broiler, melt the chocolate.
For each cake pop, place a bit of chocolate into the bottom of an ice cream cone. Press some of the leftover cake pop mixture into the cone. Dip the cone into the chocolate, then remove one of the cake pop balls from the freezer and press it on top. Allow the chocolate to harden (this will help keep the cake pop in place), then dip back into the chocolate so that the entire top is coated in chocolate. Immediately top with some sprinkles. Repeat with all of the cake pops, then allow the chocolate to set and enjoy!