To prepare the pie crust, combine the flour, sugar, and salt together in a mixing bowl. Add the butter and work it into the flour with your hands or in a stand mixer with a paddle attachment. Once it resembles very course sand, add the ice cold water a bit at a time until it comes together when pressed. Cut off 1/4 of the dough and wrap both pieces with plastic wrap. This portion will be for the lattice top. Refrigerate for 45 minutes.

In a saucepan, combine all the ingredients for the filling over medium heat. Let it come to a bubble and set aside to cool down.

Preheat the oven to 350F. Meanwhile, roll out the larger portion of pie dough and roll it out until it's 1/8" thick and has about an 1/2" overhang once placed into the 6" pie pan. Gently press the pie dough into the pie tin edges. Prick a few holes on the bottom with a fork. Refrigerate.

Roll out the second portion of pie dough to a 7" circle on a sheet of parchment. Cut out 1/2" wide strips to create the lattice top. Pour the berry mixture into the prepared pie tin. Slide the lattice top onto the pie. Press the edges together. Brush the crust with the lightly whisked egg and bake for 20 minutes or until golden brown. Set aside to cool before serving.

Combine all the ingredients, besides the whipped cream and cherry, in a blender. Blend just until smooth. Top with whipped cream and a cherry.