In a large bowl, cream butter and sugar until light and fluffy. Add eggs, one at a time, beating well after each addition. Beat in lemon zest. Combine 3 cups flour, almonds, baking powder and salt; gradually add to creamed mixture until mixture resembles coarse crumbs (do not over mix).
Set aside 1 cup of dough. Press the remaining dough into a greased 15x10x1-in. baking pan. Spread preserves to within 1/4 in. of edges. Combine the reserved dough with the remaining flour; sprinkle over preserves.
Bake at 350° for 25-30 minutes or until lightly browned. Cool on wire rack. Cut into bars.