Make the Pie Crust:

1. In a large mixing bowl or stand mixer, combine flour, brown sugar, and salt. Add cold, cubed butter and mix until the butter is broken down into pea-sized pieces. If mixing by hand, use your palms to smear the butter into the flour until the mixture begins to clump together.
2. Slowly stream in the ice water and apple cider vinegar while mixing, just until the dough comes together but remains slightly shaggy. Don’t overmix!
3. Form the dough into a disc, wrap tightly in plastic wrap, and refrigerate for at least 30 minutes.
4. Preheat your oven to 375°F.
5. On a lightly floured surface, roll out the chilled dough until it’s large enough to fit a 9-inch pie dish with some overhang. Carefully transfer the dough to your pie dish, trim the excess, and crimp the edges decoratively.
6. Line the crust with parchment paper and fill with pie weights, dried beans, or an oven-safe cake pan to weigh it down.
7. Blind bake for 15-20 minutes, then carefully remove the weights and parchment. Return the crust to the oven and bake for an additional 5-10 minutes, until lightly golden. Remove and let cool slightly.
8. I got the recipe for this pie crust from a pastry chef (thanks Kelly!!!) that I will tag when I find her blog.

Prepare the Filling:

8. While making your crust, preheat a separate oven (or the same oven before blind baking) to 400°F. Roast or boil the purple sweet potatoes until fork-tender, about 30-45 minutes for roasting.
9. Let the sweet potatoes cool enough to handle, then peel and mash them thoroughly until completely smooth with no lumps. You should have 2 cups of mashed sweet potato.
10. Lower the oven temperature to 350°F.
11. In a large bowl, whisk together the mashed sweet potatoes, sweetened condensed milk, evaporated milk, eggs, melted butter, and vanilla extract until well combined.
12. Add the brown sugar, cinnamon, ginger, nutmeg, salt, and orange zest. Mix until the filling is silky smooth.
13. If desired, add 2-3 drops of blue food coloring and 1-2 drops of red food coloring to deepen the purple hue. Mix thoroughly.
14. Pour the filling into the pre-baked pie crust and smooth the top with a spatula.

Bake the Pie:

15. Bake at 350°F for 45-50 minutes. The pie is done when the edges are set but the center still has a slight jiggle (it will continue to set as it cools).
16. Remove from the oven and let cool on the counter for 20-30 minutes.
17. Transfer to the refrigerator and chill for at least 2 hours before serving.

Decorate and Serve:

18. Just before serving, crush the Oreo cookies and press them around the crimped edges of the pie for a fun, festive look.
19. Optionally, top with whipped cream, additional cookie crumbles, or candied pecans.
20. Slice and serve chilled.