Start with the filling and placing all the ingredients into a large bowl and toss until everything is well coated. Let the mixture sit will you prepare the dough.
Place the dry dough ingredients into a food processor and pulse just until combined. Add in the cold cubed butter, eggs and maple syrup and pulse 4-5 times and the ingredients are loosely combined.Add in the water a couple tablespoons at a time and pulse just until the dough comes together. Some parts of the dough might still look dry and that's okay. Remove the dough from the processor and kneed it 3-4 times until it comes together. Separate the dough into two evenly sized pieces. Place one of the discs between two pieces of parchment paper. Roll the dough out until it's roughly 1/8" in thickness and then carefully transfer the dough to the pie crust and trim any extra edges.
Roll out the other half of the dough until it's in a rough circle and about 1/8" in thickness. Use a pizza cutter to cut 1/4"-1/2"strips (or whatever size you like). You will need about 8-10 strips in total. Fill your pie crust and lay 4-5 strips over the filling. Fold every other strip up and then lay a strip perpendicular to the other strips. Unfold the strips and repeat with every other strip until you have used all the strips. Fold over the edges and crimp them using your fingers or a fork.
Whisk together the egg wash and brush it over the all the strips and the edges. Cut out star shapes in the remaining dough and place them on top of the egg washed strips. Brush egg wash over cut outs as well. Sprinkle with decorating sugar for extra sparkle and sweeteness! Bake at 350 F for 25-30 minutes and crust is golden brown.
Store the the pie covered in the refrigerator for up 4 days.