In a large bowl, combine the first seven ingredients. Cut in butter until mixture resembles coarse crumbs. Add eggs and lemon zest; stir until mixture forms a ball. Divide into fourths. Cover and refrigerate for 3-4 hours or until chilled.
Remove two portions of dough from refrigerator; press each into an ungreased 9-in. fluted tart pan with removable bottom. Spread 2/3 cup jam over each.
Between two sheets of lightly floured waxed paper, roll one portion of remaining dough into a 10×6-in. rectangle. Cut six 1-in.-wide strips; arrange in a lattice design over jam. Repeat with remaining dough (return dough to the refrigerator if needed).
Bake at 350° for 40-45 minutes or until bubbly and crust is browned. Cool completely.
Cut them into triangles and dust with confectioners’ sugar if desired and serve.
