In a bowl, combine the raspberries, starch, tapioca, and sugar.
Split the pie dough into two pieces.
Roll out one piece on a floured surface. Roll the dough about 1/2 an inch larger than your pie pan.
Lay the rolled dough in the pie pan and press down lightly on the bottom and up the sides of the pan.
Pour the raspberry filling into the bottom pie crust.
Dot the top with 1 tablespoon of butter that you've cut into small chunks.
Roll out the other half of the dough. If desired use a small heart cookie cutter to make cut out hearts as you would like.
Lay the rolled out dough over top of the filling. Fold the top edges of the dough under the bottom dough layer and use your fingers to pinch/seal it together.
Bake at 350℉ for 55-60 minutes, or until the crust is lightly browned.
Allow the pie to cool completely before slicing so the filling has time to firm up.
Serve and enjoy!