So I've seen these all over the place, but have actually only ever tried them 2 times (by trying, I mean tasting, not making). Most recently, while on a little vacation in New Orleans, one of the companions on our trip brought down some "cake bombs" from a place in Chicago called Bleeding Heart Bakery. Though I'm not sure how they made theirs, I was pretty sure it was similar to what I'd heard went into a cake pop (minus the popsicle stick), and I adored how they covered some of their flavors in cocoa nibs and hazelnuts, so that's what I opted to try when making my own.
So, I think you're supposed to mix cake with frosting until mushy enough to form into a ball. I didn't have any leftover frosting, but did have some leftover strawberry curd, so figured I'd give that a shot instead. Can't say for sure that the treats have a very strong strawberry flavor, but they are delightfully chocolatey. I made my basic chocolate cake but in true 9x13 inch cake form instead of cupcakes (and baked for 45 minutes, instead of 20). I crumbled some pieces into a bowl and mixed with the curd and formed them into balls. Sorry for the lack of precise measurements; true to form, I wasn't really keeping track. I put mini popsicle sticks into the balls and froze them for about 10-15 minutes, then coated them with melted dark chocolate. I didn't bother too much with tempering since I was going to cover them all over with topping anyway, but I would recommend adding a little vegetable oil to the chocolate so that it cuts down on the bloom (something I have a huge problem with, but hear tell that some people don't struggle with it nearly as much as I do). I let the chocolate drip off and then rolled them in nibs and chopped hazelnuts and laid them out to dry on parchment paper. They only took about 10 minutes to harden.
I will test them out at the office tomorrow, and say that they are a Valentine's day treat. I mean, it is chocolate, right? Chocolate = Valentines Day. If they go over well, I will probably keep it in mind if I ever have any leftover cake and frosting, that these would be a good way to use up leftover ingredients.