When you’ve made this creamy icing, it’s best to refrigerate it for a while to let it firm up, before you you it to ice your cake.
If you’d like to save time on the day of serving the cake, you can make this ahead! Just store it in the refrigerator for up to three days, and whip it on high speed, briefly, before using. I usually make this the night before, and when I’ve iced the cake in the morning, I keep it in the fridge until it’s time to serve. This is, without a doubt, the prettiest and yummiest icing I’ve ever made. I highly recommend giving it a try!
16 ounces (2 bars) full-fat cream cheese, softened at room temperature for at least 1 hour
1/4 cup Gold Medal all-purpose flour
1 cup Domino white sugar
1/4 teaspoon salt
1 cup McArthur whole milk
1 teaspoon vanilla
Place the softened cream cheese in the bowl of a stand mixer (or simply use a large bowl and hand beaters). Whip the cream cheese on high speed for several minutes, until it is completely smooth and silky. Scrape the cream cheese out into a separate bowl and set aside.
Whisk the flour, sugar, and salt together in a small saucepan. Turn the heat on to medium and slowly add the milk, whisking constantly. It will look lumpy at first but whisk vigorously to create a smooth paste. Continue whisking as the mixture comes up to a simmer. It will thicken rapidly and dramatically as it comes to a boil (see photo below). Simmer for 1 full minute, then turn off the heat. Scrape the flour and milk paste into the mixer bowl. (If you want to be 100% sure there are no small lumps, pour it through a mesh sieve.)
Turn on the mixer or beaters and whip the flour-milk mixture for 10 minutes, or until it is lightened and no longer piping hot. It should be lukewarm or cooler. Slowly add the whipped, softened cream cheese, whipping constantly. Add the vanilla. Continue whipping until the the two are completely combined and smooth and silky.