For Pastry-Sift flour, salt, and sugar together. Cut in butter and peanut butter until mixture resembles coarse crumbs and ingredients are well mixed. Stir in eggs and blend well.
Knead dough slightly and shape into a ball. (Dough will be soft) Wrap in waxed or parchment paper and refrigerate for 20 minutes.
Preheat oven to 350. For filling-combine peanut butter, granulated & brown sugar, flour, eggs, milk and vanilla.
For each tart-place 1 well rounded tablespoon of dough into each ungreased miniature muffin cups. Press and shape dough to form pastry shell. Spoon 1 tablespoon of peanut butter filling into each tart. Bake for 25 minutes, or until filling is golden brown. Cool 5 minutes before removing from muffin pan.