Mix all the filling ingredients together except for the butter. Stir until just barely combined.
Place the mixture in a 9×13-inch pan. Dot with butter.
Roll the pie dough out into a rectangle about 1/4 inch thick. Cut out stars or other shapes with a cookie cutter, or leave it whole. Place on top of the crisp.
Whisk together the egg and heavy cream. Brush a thin, even layer over the pie dough on top. Sprinkle sugar over the crust.
Bake the crisp at 350°F for about 1 hour, or until bubbling in the middle and golden on top (it may take slightly longer if you used frozen berries). Let it sit for about 30 minutes before serving.
