large flower nail(optional but highly recommended; helps the cake bake evenly)
Cake turntable(optional, but makes smoothing the frosting much easier)
rounded measuring spoon(to make indents in the frosting; I recommend a metal measuring spoon and used a rounded ¼ teaspoon)
Small acetate sheet(or small flexible piece of plastic; to smooth frosting. A folded piece of parchment or wax paper can work, but will tend to leave lines in the frosting.)
Preheat oven to 350°F (177℃). Prepare a 6-inch half sphere pan with baker's floured cooking spray (or grease and flour pan well). Place flower nail in the base of cake pan.
Combine melted butter, buttermilk, eggs, and vanilla in a large bowl and mix until combined. Add in cake mix and stir until moistened (about 30 seconds), then beat on medium speed for about 2 minutes.
Pour batter into prepared pan (I didn't use all of the batter; an overfilled sphere pan will overflow and make a mess in your oven). Batter level should be about a centimeter (not quite half an inch) below the cake pan rim. (Might not hurt to place a baking sheet in the oven below the pan just in case.)
Bake for 35-45 minutes, (or until a toothpick inserted in the center comes out clean). Allow to cool for 10 minutes before removing cake from pan.
Cool to room temperature before decorating. (Place in the fridge to accelerate the cooling process if desired.) While you’re waiting…make your frosting!
Frosting
Beat together butter and shortening; beat in powdered sugar and vanilla until well combined.
(If using frosting whitener, remove ½ cup of frosting into another bowl - color this deep green for the 'grass' frosting border. Add whitener to remaining frosting.) If not using whitener, remove ½ cup of frosting and color it green whenever you'd like :)
Add milk if needed until frosting reaches an easily spreadable consistency.
Assembly & Decorating
(If desired, use a cake leveler or large serrated knife to slice cake into 2 or 3 layers to fill with frosting).
Place a smear of frosting on a plate or cake circle (to keep the cake from sliding while you decorate it) and center cake in the center of the circle. Spread a thin coat (crumb coat) of frosting around the outside of the cake and chill in the fridge for 10 minutes.
Once your crumb coat has set, add another thicker layer of frosting to the outside of the cake and smooth. I used a small offset spatula and credit-card-sized piece of acetate for this part. Set cake in the fridge for about 10 minutes to semi-set the frosting.
(This will be the most time-consuming step-) Make the golf ball indents! Gently press the back of a rounded measuring spoon into the frosting and rotate it out to form an indent in the frosting. I found it helpful to very lightly grease the back of the spoon with a bit of cooking spray every 4-5 indents. If you're having any trouble at this step - first, make sure you twist/rotate the spoon out of the frosting. Pulling it straight out will deform the indent. Next, I found a metal spoon worked better than a plastic one. You can try heating it or wetting it if just the oil isn't working well enough. Chilling the cake may also help. (More details in the post intro if you're having trouble - and please leave a comment or shoot me an email if the divots still aren't working.)
Transfer green frosting to a piping bag fitted with a grass tip, and pipe a rim of grass around the cake base. High-five yourself on your awesome cake - and enjoy!
Video
Notes
(Please note nutrition information is an estimate and may not be exactly accurate.)