Make the filling: beat the cream cheese in a large bowl with a hand mixer until smooth, about 30 seconds. (crazyforcrust.com)
In a stand mixer with the paddle attachment (or large mixing bowl with a hand mixer) beat the butter and sugars at medium speed for 2 minutes, until light and fluffy. (tasteslovely.com)
In a separate bowl with a hand mixer or in the bowl of your stand mixer fitted with the whisk attachment, whip the egg whites into soft peaks. (glutenfreeonashoestring.com)