Blend the flour, 2/3 cup crushed Ritz crackers, salt and butter with an electric mixer until roughly combined; small lumps of butter should still be visible. Combine the water and vinegar and add liquid slowly just until the dough comes together. Remove the dough, pat into a ball and cut in half. Flatten each half in plastic wrap into a thick disk. Wrap well and refrigerate for 1 hour.
To prepare the crust, remove dough and let it sit for 30 minutes at room temperature, then roll on a light floured surface into a 1/8 inch thick crust. Cut circles out of the dough and gently press the crust into the edges of well-greased miniature tart pans or miniature cupcake trays, trimming away any excess crust.
For the filling, combine the sour cream, mayonnaise, cheese, spinach and artichoke hearts in a large bowl and mix thoroughly.
Sprinkle crushed Ritz crackers over the bottom of each tart. Next, spoon one tablespoon of filling into each tart.
Bake at 375F until tarts are fully cooked and cheese begins to turn golden (about 30 minutes).
Remove tarts from the oven and insert one Ritz cracker into the filling of each tart, cool and serve.