Combine butter and flour in the bowl of a mixer and beat on medium speed for 1 minute. Scrape down the sides of the bowl and then beat for 1 minute more, Set aside at room temperature.
Create apple filling according to directions in the recipe linked below.
Spray cooking oil (Pam) onto a piece of plastic wrap, and place over the braid. Proof at room temperature or, if possible, in a controlled 90 degree F environment for about 2 hours, or until doubled in volume and light to the touch.
Bake for 10 minutes, then rotate the pan so that the side of the braid previously in the back of the oven is now in the front. Lower the oven temperature to 350 degrees F, and bake about 15-20 minutes more, or until golden brown.