Preheat oven to 375 degrees F. Lightly oil a 9-inch tart pan with a removable bottom or coat it with nonstick spray.
To make crust: Spread oats in another pie pan and bake, stirring occasionally, until toasted, 6 to 12 minutes. Let cool. Place the oats in a food processor and process until coarsely ground.
Stir together oats, flour, sugar, baking powder and salt in a large bowl. Drizzle oil onto dry ingredients and use a fork or your fingers to blend until crumbly. Using a fork, stir in water, 1 tablespoons at a time, until dough just comes together.
Turn the dough out onto a floured surface and knead 7 to 8 times. Roll dough out to an 11-inch circle, dusting with flour if necessary. Transfer dough to prepared pan, pressing to fit. Trim edges. (If necessary, use scraps to patch any holes in crust.).
To make filling & bake: Spread 1/2 cup pecans on a baking sheet and bake for 5 to 10 minutes, or until fragrant. Let cool and coarsely chop.
Whisk brown sugar, eggs, egg whites, corn syrup, vinegar, butter, vanilla and salt in a medium bowl until smooth. Stir in dried cranberries and chopped pecans. Spoon filling into crust. Arrange remaining 1/2 cup pecans on top of filling.
Bake tart for 20 to 25 minutes, or until filling is set and crust is golden. Cool completely in the pan on a wire rack.