2/3 cup old-fashioned oats
1/2 cup all-purpose flour
1/2 cup 'white' whole wheat flour
1/4 teaspoon baking powder
1 teaspoon sugar
1/4 teaspoon kosher salt
1/2 cup cold unsalted butter, cut into small pieces
1 teaspoon cider vinegar
5-6 tablespoons ice water
In the bowl of a food processor fitted with the blade attachment, combine oats, both flours, baking powder, sugar and salt and pulse a few times to combine. Add the cold butter and pulse until mixture becomes crumbly. Add the cider vinegar and 5 tablespoons of the ice water, pulsing just until the mixture starts to form a soft dough. If the mixture feels dry, you can add up to one additional tablespoon of ice water. Scrape the dough out onto a piece of plastic wrap, pat into a disc, wrap and refrigerate for at least 30 minutes before rolling out.
Place chilled dough on a sheet of parchment paper that has been lightly dusted with either white or whole wheat flour. Roll the dough into a circle, about 12 to 13 inches wide. Place the dough into a 9" pie plate (do not use a deep dish plate; my pie plate measures 1 and 1/4" deep.) Let the dough drape over the sides of the pie plate; do not crimp. Set aside while you prepare the filling.
Preheat your oven to 425 degrees.
Jumble Berry filling with a handful of Fresh Apricots
7 cups total of fruit (I used one package of Trader Joes frozen mixed berry medley, fresh blackberries that I had on hand and a few fresh apricots sliced in wedges. You can also make this with frozen raspberries and fresh peaches.)
1 cup granulated sugar
3 tablespoons light or dark brown sugar
1/2 teaspoon cinnamon
1/8 teaspoon freshly grated nutmeg
5 tablespoons cornstarch
zest of 1 small lemon
Place the fruit in a large bowl and use your fingers to gently break the fruit apart so it is not frozen in one big clump. In a medium bowl, whisk together the sugar, brown sugar, cinnamon, nutmeg, cornstarch and lemon zest. Pour this over the fruit and use a rubber spatula to gently combine, making sure the frozen berries and sugar are well mixed. Place the fruit mixture into the pie plate, spreading it evenly with an offset spatula. Gently use your fingers to bring the overhang of dough up and over the edge of the filling, as you would if your were making a free-form tart or galette. Sprinkle the edge of the crust with sugar, if you wish. Place on a parchment lined baking sheet and bake at 425 degrees for 15 minutes. Reduce the heat to 375 degrees and bake for an additional 50 minutes or a bit more, until the filling is bubbling thickly and the crust is golden. If you can wait, it is best to let this cool on a rack for at least one hour before slicing.