This past Sunday, I got a craving for something sweet. Only problem – it was 9:00pm! Deciding that was too late to venture out to the store for anything (I guess I could have gone shopping, but seriously, who wants to do that at 9:00pm?!), I decided to whip something up with what I had on hand.

Lucky me, I had a box of Pillsbury Key Lime cake mix in the pantry 🙂 While box mixes may not be as exciting as homemade goodies, they really are delicious and convenient – especially for late night sweet attacks!

My mind made up, I whipped up the batter, put it into my muffin/cupcake pan, and threw it into the oven. Commence cupcake excitement!!!

Then I was met with a dilemma – what to put on top of the cupcakes? I didn’t have any frosting in the pantry…and I’d never made frosting before. Guess there’s a first time for everything!

I found what appears to be the Holy Grail of buttercream recipes online here:

The Ingredients

• 5 Tbsp. flour
• 1 cup milk
• 1 tsp. vanilla
• 1 cup butter
• 1 cup granulated sugar

The Instructions

• Whisk flour into milk in a small saucepan, stirring constantly until it thickens (like brownie mix).
• Remove from heat and cool to room temperature (I actually put it in the freezer to get it to cool down quickly!).
• Stir in vanilla.
• Cream butter and sugar together until light and fluffy.
• Add the liquid mixture and “beat the living daylights out of it!” You’re looking for it to resemble whipped cream here (and you really can’t overmix this).
• Done! Top cupcakes with this deliciousness and enjoy!

This sounded great except, I didn’t have all the ingredients on hand. We hardly ever have milk in the house (my fiance doesn’t drink it, and I never manage to finish a whole carton), and I didn’t have enough real butter either. I decided to just wing it and see what would happen if I replaced the milk with water (great lactose intolerance solution in baked goods!) and used Imperial (margarine) instead of real butter.

The results…well, they started out well. After my stand mixer beat the buttercream into submission, I tasted it, and it was delicious! Very light like whipped cream but with more substance (i.e. it didn’t immediately disappear on the tongue – which is win in my book!). It perhaps was a bit too sweet for my taste. Unfortunately though, that didn’t matter because once I got the cupcakes cooled enough to frost them and attempted a nice swirl (which also was hilarious using an improvised piping bag!), the buttercream had started to break 🙁

By the time my fiance and I got to eat them, the cupcakes were yummy and limey, but the buttercream…well, it was more like butter. Sweetened and whipped butter, but still just butter. Not so lovely!

Reading the comments on the buttercream recipe, I realized that Imperial is apparently the worst possible butter substitute to use for making frosting – sad but I have to agree! Some people commented that Blue Bonnet is a good substitute, so I may try that next time 😉

For now though, I only frosted a few of the key lime cupcakes, so we can definitely enjoy the rest “dry!”