Christopher Kimball’s Milk Street on Instagram: "To go with our basic Yellow Blender Cake, we created 1-2-3 frosting: a frosting recipe with a formula that’s so easy to remember that you’ll never need the recipe again. It’s the kind of recipe that Julia Child used to make off the top of her head, a customizable template for lots of flavorings. And we think it’s genuinely better than a buttercream, which can taste like a cloyingly sweet stick of butter, with noticeable sugar granules; our baking