In large bowl, combine first nine ingredients. Set aside.
Cut each tenderloin horizontally from long side to within 1/2-inch of opposite side. Open so meat lies flat; cover with plastic wrap. Flatten to 1/2-inch thickness; remove plastic wrap. Spread spinach mixture over each tenderloin to within 1-inch of edges. Roll up jelly-roll style, starting with long side; tie at 1-inch intervals with kitchen string. Place seam side down on greased rack in shallow roasting pan; brush with oil.
Bake, uncovered, at 425° 45 to 60 minutes or until meat reaches desired doneness (for rare, meat thermometer should read 140°; medium, 160°; well-done 170°). Let stand 10 minutes. Cover and refrigerate until chilled. Discard kitchen string; cut into 1/2-inch slices.