Balancing cupcakes and buttercream

[Last_Dance]

A couple of weeks ago I attended a cooking class focused on cupcakes. I'm planning to try a couple of basic recipes (vanilla cupcakes and buttercream) this week-end.

The problem is, they were given as separate recipes. So, while I'll get (about) 18 cupcakes, the recipe for buttercream calls for 9 oz. of butter.

It sounds a bit much for 18 cupcakes, especially because my other cupcakes-and-buttercream recipe only calls for 3.5 oz. 
I tried that months ago and I remember having more than enough icing for 12 cupcakes - as in "having to eat a couple of spoonfuls straight from the bowl"   

Any suggestions? Also, does anyone know how long buttercream keeps?

(My apologies if I've used the wrong terminology and/or measurements) 

[Shotochick]

I am of the school of thought that you can never have too much buttercream (100% icing and I am a happy girl, who needs cake really?!?!?)

But for those that like balance in their cupcake life, I usually aim for a batch of 2 cups of icing for 24 cupcakes (gives a little for tasting to 'make sure'). Which would be about 250g of butter and 2 cups of icing sugar plus whatever flavors you are adding. (Sorry can only think in grams/cups).

[Sheila Take a Bow]

You can freeze your buttercream if you make too much.  Just thaw it and beat it again (if it looks like it needs it) and you can use it for your next batch of cupcakes.

If you're not experienced with buttercream it might be easiest just to make the recipe you have instead of worrying about scaling the recipe, and then freeze the excess.

[Bethalize]

The trouble with buttercream is that it depends on what you are doing with it. If you flat-ice a cupcake with buttercream you'll need less than if you do a rose swirl or the Wilton 1M swirl. I just today used 250g butter/500g icing for 18 cupcakes and I don't have much over. If I'm feeling mean I can squeeze it out of 200g. 9oz is 250g.

Keeps for a week (if you put milk in it), freezes well.

[Pioneer]

Spread the extra buttercream between graham crackers for a quick cookie-like snack.  Store at room temperature.  We used to purposely make too much so that we could indulge in these treats.

[Last_Dance]

Thank you all for answering.

I'm planning to practice with a piping bag, so we'll see how much icing will be left, then I'll probably freeze it.
Thank you again!

[Maggie]

I know you are new here but it is almost against the rules to post a question like that and not post the recipes.  I am always looking for a new cupcake or icing recipe    So would you please share? 

[Last_Dance]

I'll do a quick translation then: it's just plain old vanilla cupcakes, but I liked how the sequence of events was spelled out. They do seem softer than my usual cupcakes.

Vanilla cupcakes

Ingredients for 18 cupcakes:
- unsalted butter 175 g.
- sugar 160 g.
- 2 eggs
- self-raising flour 160 g.
- pastry flour 100 g.
- whole milk 200 ml.
- vanilla extract

Mix together room-temperature butter and sugar using an electic whisk (I did this for about 5 minutes).
Add vanilla extract and eggs.
Sift both kinds of flour and add them little by little, alternating them with milk.
(If you're planning to add fruits or bits of chocolate, this is where they go in)
Pour the mix in a muffin pan and bake in a pre-heated oven at 180° for 20 - 25 minutes.

Buttercream

- room-temperature butter 200 g.
- icing sugar 400 g
- vanilla extract

Whisk the butter for 2 minutes with an electric whisk, sift the sugar and add it slowly to the butter as you keep whisking.
Add vanilla extract, keep whisking until you obtain a light, fluffy cream.

If you want something less sweet, you can use 250 g of butter and 250 g. of sugar.