Vanilla Buttercream Frosting

Last born had a birthday on Sunday. After warm spinach-artichoke dip and zingy cucumber dip; after frozen strawberry margaritas whose fruit factor was boosted with homemade strawberry jam; after burgers and hot dogs sizzling from the grill,  sweet and bacony baked beans, and potato-egg salad with fronds of fresh dill (that I should have chopped…