For the Oat Wheat Pie Crust

• 1 cup rolled oats
• ½ cup whole wheat flour
• 1 cup all-purpose flour
• ¼ cup firmly packed dark brown sugar
• ½ teaspoon salt
• ¾ cup (1½ sticks) cold unsalted butter, cut into cubes
• ¼ cup milk

For the Butterscotch Pudding

• 6 large egg yolks
• ¾ cup granulated sugar
• ¼ cup heavy cream
• ½ cup firmly packed dark brown sugar
• ⅓ cup cornstarch, sifted
• 1 teaspoon salt
• 3 cups whole milk
• 1 vanilla bean
• 1 tablespoon unsalted butter
• 2 tablespoons whiskey

To Assemble the Tarts

• 1 Butterfinger candy bar, broken into small pieces

Make the Oat Wheat Pie Crust

Put the rolled oats in a food processor and process for about 30 seconds, until ground but not powdered. Add the flours, brown sugar, and salt and pulse until combined.

Add the butter and pulse until the butter pieces are small and the dough looks crumbly, like coarse sand. Add the milk and pulse for a few seconds.

Scoop the dough out of the food processor and form it into a large disk. Wrap tightly in plastic and refrigerate for at least 1 hour and up to 3 hours.

Dust a work surface with a sprinkling of flour. Unwrap the disk of chilled dough and put it directly on the work surface. Cut the dough into eight equal pieces, about 2 ounces each, and gently shape each piece into a smooth disk. The dough will be sticky. Make sure to turn the dough over (use a spatula or a bench knife) as needed and keep the working surface floured. Put the dough disks in the refrigerator for 10 minutes.

Using a rolling pin, roll each dough ball into a 6-inch round just over ⅛ inch thick. Place a round over a 4-inch tart pan and very gently press the dough into the pan. Roll the rolling pin over the pan to trim off excess. Repeat with the remaining dough rounds. Use any excess dough trimmings to make a ninth tart shell or freeze them for another time.

Preheat the oven to 325 degrees F.

Put the tart pans in the freezer for 30 minutes.

Remove the tarts from the freezer, then arrange on a baking sheet and gently prick the dough with a fork.

Bake on the baking sheet until golden brown, 12 to 15 minutes, rotating the baking sheet halfway through the baking time.

Transfer the tart pans to wire racks and let cool completely.