I did the buttons differently this time. It was a little faster, and they came out just as cute. Instead of indenting the center, I just used the large end of a piping tip to press a circle onto each button. A bamboo skewer is just the right size for the center holes.
For the cake, I used Martha Stewart's one bowl chocolate cake recipe again. It's super dark, almost Oreo-colored, and perfectly moist. It's actually not very sweet, despite having three cups of sugar in the batter; the cocoa offsets the sweetness. It pairs really well with the vanilla buttercream, which has just a hint of almond extract.
Oh! And lest I forget to give credit where due, I took inspiration for the frog from this great tutorial. It's not in English, but the pictures work in any language!
The hostesses loved the cake, and I hope the mom-to-be did, too!