Cut each pastry sheet into quarters; roll each quarter into a 6-in. circle. Transfer pastry to eight ungreased 4-in. fluted tart pans with removable bottoms. Trim pastry even with edges. Place on baking sheets. Bake at 450° for 5-6 minutes or until golden brown. Cool on wire racks. Reduce heat to 350°.
Place raisins in a large bowl. Cover with boiling water; let stand for 5 minutes. Drain. In another bowl, beat the brown sugar, eggs, butter, syrup and flavoring; stir in raisins. Divide filling among tart shells.
Bake for 16-20 minutes or until centers are just set (mixture will jiggle). Cool on a wire rack. Serve with ice cream if desired. Yield: 8 tarts.