In the bowl of a standing mixer (or in a large bowl if you are using a pastry cutter or fork), mix flour, salt and lemon zest together.
With your mixer on low (or with your pastry cutter), work the butter into the flour mixture (a little at a time) until the mixture resembles coarse crumbs.
Add in ice water, 1 Tbsp at a time, until the dough just comes together (I used approx. 6 Tbsp).
Turn dough out onto a floured surface, cut in half and form each into a ball (or a disc), cover in plastic wrap and chill for at least 30 minutes.
When you’re ready to make your pie, preheat oven to 425 degrees.
Mix strawberries, rhubarb, granulated sugar, brown sugar, salt and ground cinnamon together.
Add in flour, cornstarch, lemon zest, lemon juice and vanilla extract and mix together. Set aside.
On a floured surface, roll out one ball of dough into a large circle, about 1/8” of an inch thick.
Transfer your dough to a large pie plate (this works for a 9” or 10” deep dish pie plate). I like to transfer the dough by loosely rolling it around my rolling pin and then unrolling it over my pie plate.
Gently press the dough into the pie plate. Remove any excess pie dough on the edges of the pie (leaving about 1/2” of overhang).
Pour strawberry rhubarb filling into the dough.
Place the 2 Tbsp of cubed butter around the pie.
Next, roll out your second pie dough into a large circle, about 1/8” thick. Cut dough into strips, using a sharp knife or pizza cutter, about 1/2” thick. Depending upon the size of your pie plate, you will need 8-10 strips.
Place 4-5 strips on your pie. Weave the remaining 4-5 strips in and out of the ones on your pie.
Crimp the edges of the pie together. Brush the edges and the strips with your egg wash and sprinkle with raw sugar, if desired.
Bake pie for 15 minutes.
Turn oven down to 375, cover the edge of the pie with a pie shield (this keeps the edges from browning too quickland bake for 40-45 minutes, or until the crust is golden and the filling is bubbling.
Allow to cool before serving (the longer the pie cools, the thicker the filling will be).
Serve with ice cream or whipped cream and enjoy!