i've just followed this recipe found from the wilton site, 1/2 cup butter, 1 package of cream cheese, 4 cups icing sugar. i folloed it and all was goung well. as soon as i started to add the icing sugar(confectionary sugar) it started to go runny! like runny custard! what did i do wrong? the butter and cream cheese where both at room temperature.
i use the crusting cream cheese recipe, featured here in the recipe section, with a few of my own tweaks added. i just keep adding in more confectionary sugar until it's the consistency i want. it's actually the icing i use 90% of the time, if not more! under fondant, as fillings, with flavorings added in..it's always good, unless it's a cake that's going to be in humid conditions or featured outdoors. (i'm in middle tennessee)
i would second more icing sugar. cant imagine that there is something 'wrong' it will probably just be a runny texture just now.
Did you use fat-free or reduced fat cream cheese? The one time I used fat-free, I got runny frosting.
with my tweaks of an extra cream cheese, marsmallow cream, vanilla bean, and extra liquid vanilla, i actually make my cream cheese runnier!!! but if you just add the confectionary sugar until it's the consistency you want, it recovers and becomes this yummy, beautiful thing!!!!