Preheat your oven to 400 degrees F and lightly spray a 9x13in baking dish with a nonstick spray. Set aside.
Flour a work surface and take two of the pie crusts out of their packaging. Place one on top of another and lightly flour the top. Roll the crust out to a 16inx12in rectangle. Place the crust into the prepared baking dish, pressing down in the corners. Leave the edges as is. You will deal with those later.
In a large bowl, combine the berries, flour, brown sugar, granulated sugar, cornstarch, amaretto liqueur, cinnamon, and lemon juice. Very gently toss the ingredients together and pour into the prepared crust.
Again, flour a work surface. Take the two remaining pie crusts and unroll them. Place one on top of the other and light flour the top. Roll the crust out to another 16inx12in rectangle. Cut 1/2 inch strips (long) from the dough and begin layering them on top of the berries to form a lattice. To do this, place half of the strips diagonally across the pie. Weave in the remaining strips to create a lattice. Trim the edges so that they are even with the bottom crust, and then pinch the sides of the crust.
Brush the pie with the beaten egg. This will help to darken the crust as it bakes.
Bake the pie for 50 minutes to an hour or until the berries are bubbly and the crust is dark brown. Remove from heat and allow the pie to cool completely before slicing and serving. Enjoy!