Toaster Tarts

2 1/2 cups all-purpose flour
1 teaspoon salt
1 tablespoon sugar
1 cup cold butter, cut into chunks
1 tablespoon apple cider vinegar
3 tablespoons cold water
Filling(s) of choice (I used homemade apple butter this time)

Preheat oven to 375 degrees.
Mix the flour, salt and sugar in a mixing bowl. Cut the butter into the flour using a pastry cutter. The mixture should look like large crumbs and begin to cling together in clumps. Sprinkle the apple cider vinegar and cold water over the dough and with your hands, mix it in until the dough holds together adding more water if necessary.
Divide dough in half. Roll one half of dough out to a 9 x 12 inch rectangle. Cut into six equal rectangles, 4 1/2 x 4 inches. Transfer to a baking sheet leaving at least two inches in between. Spoon at least a tablespoon of filling down the center of each rectangle. Roll out other half of dough and cut into six rectangles as above. Put the "tops" on and crimp all edges with a fork. Prick holes down the center of each tart. If desired, sprinkle liberally with cinnamon sugar.
Bake at 375 degrees for 20 to 25 minutes, until golden brown.