1. Make the crust: in a food processor, pulse together the flour, sugar and salt until combined. Add the margarine and pulse 5-7 times until crumbly. Add the cold water and pulse 5-7 more times until the dough just comes together. No food processor: cut in the margarine with a pastry cutter, then sprinkle in the water a tablespoon at a time, tossing with a fork, until it comes together (don't knead).
2. Turn the dough out and knead briefly, about 30 seconds, just until incorporated. Don't overwork it or the crust will turn out tough. Wrap tightly and refrigerate until ready to use.
3. Preheat the oven to 350°F.
4. Make the cinnamon sugar: stir together the sugar and cinnamon, set aside.
5. Make the filling: combine the sugars, flour, cinnamon, allspice, nutmeg, ginger and salt. Cut in the margarine until crumbly.
6. Add the apples, lemon juice and vanilla, stir until coated.
7. Roll out half the crust dough to a 12x12" sheet. Scoop 1 Tbsp of filling in 3 rows of 4, leaving 1" between scoops. Roll out the remaining dough into a second 12x12" sheet.
8. Place the second sheet on top, press down between and around each mound to seal.
9. Cut into 3x4" squares (12 total), crimp the edges with a fork.
10. Bake 18-25 minutes, until browning.
11. Sprinkle immediately with cinnamon sugar. Cool slightly before serving.
