In a large bowl, mix together sugar and tapioca (or cornstarch). Add cherries and almond extract and mix to combine. Set aside for 15 minutes (or 60 minutes for frozen cherries).
Add bottom crust to pie tin. Stir cherry mixture and add to pie crust.
Cut slits or design in second pie crust (which allows steam to escape), or if preferred, create a lattice top. Place on top of the pie. Roll and crimp edges of pie crusts to seal, creating a pattern if desired (trim edges if needed).
In a small bowl, beat egg and milk together. Carefully brush the entire pie crust top with the egg wash mixture. Sprinkle with coarse sugar if desired.
Cover pie edge with foil (or a pie crust shield). Bake pie for 25 minutes (or 50 minutes for frozen cherries). Remove foil and bake for 25-35 minutes, or until top is browned.
Cool on a cooling rack. Slice and serve with ice cream or whipped cream!
*if using sour cherries, add 1 ¼ - 1 ½ cups sugar.