Almond Cream Filling

In a food processor, pulse the almond paste and sugar until the almond paste is in fine particles. Add the butter and pulse until incorporated. Scrape down the sides. Add the egg, vanilla, and flour and pulse just until incorporated. It will be a soft cream. (To make in a stand mixer fitted with the flat beater, mix the almond paste and sugar on low speed. Add the butter and continue mixing unt