This recipe is from Ree Drummond's site www.thepioneerwoman.com; contributed by Missy Dew. The title alone got me interested and then I read the ingredients. I had everything on hand and tried it yesterday. It's really not like any other frosting I've ever had. Even my teenage son asked "what is this?"...and not in a bad way! Try it and you will be in love with this recipe. I put it on chocolate cupcakes. Divine.
In a small saucepan, whisk flour into milk, stirring constantly, until it thickens. You want it to be very thick, thicker than cake mix, more like a brownie mix is. Remove from heat and let it cool to room temperature. It must be completely cool before you use it in the next step. Stir in vanilla.
While the mixture is cooling, cream the butter and sugar together until light and fluffy. You don't want any sugar graininess left. Then add the completely cooled milk/flour/vanilla mixture and beat the living daylights out of it. If it looks separated you haven't beaten it enough! Beat it until it all combines and resembles whipped cream.
Now it's ready to spread on a cooled cake. Enjoy!
(My own suggestions: Let the sticks of butter soften somewhat before you start creaming with the sugar and use a deep bowl. I had butter chips flying everywhere. And use a non-stick saucepan. The flour/milk mixture came right out.)