Combine all purpose flour, 2 tablespoons whole wheat pastry flour, sugar and salt in a large bowl. Add butter and using your hands or a pastry cutter, mix together until flour resembles coarse sand and butter is size of small peas. Add buttermilk and quickly mix together with hands until dough barely holds together. Pat into a disc, cover with plastic wrap and refrigerate for at least 1 hour.

Roll out dough on parchment paper (placing piece of plastic wrap on top of dough for rolling, if desired), into a 12-inch circle. Place on baking sheet and chill for 10 minutes in fridge while you prepare filling.

Preheat oven to 400 degrees F.

In another bowl, toss apples with lemon juice, maple syrup, 2 tablespoons whole wheat pastry flour and cinnamon.

Arrange filling in center of pastry circle to within 1½ inches of edges. Fold and pleat edges of dough up and over apples. Sprinkle with vanilla sugar.

Bake 35-40 minutes or until crust is golden and apples are tender. Let cool for 10 minutes before slicing.